For this particular issue (i.e. 'Could not load plugin') it would be good to understand the contents in the Flash plugin folder, which can be found by going to [Windows Key]+R and entering "%LOCALAPPDATA%\Google\Chrome\User Data\PepperFlash".

Under that directory there should be a version folder (e.g. 23.0.0.166, 23.0.0.181, etc...)  Knowing what's in the directory would be helpful (filenames/sizes).

It would also be interesting to know:

Version of Chrome
Platform (Win/Mac/etc)
Bit-ness of Chrome (32-bit channel, 64-bit channel)
Whether any antivirus software is present on the machine

Anthony, where can user look to provide PepperFlash data on Mac ?

Currently having a problem with this and was told to post info about my Chrome app here.

Version of Chrome: 
Google Chrome	53.0.2785.143 (Official Build) (64-bit)
Revision	f33d44362232c20d1ce2111c53ea8730698f3c88-refs/branch-heads/2785@{#925}
OS	Mac OS X 
Blink	537.36 (@f33d44362232c20d1ce2111c53ea8730698f3c88)
JavaScript	V8 5.3.332.47
Flash	23.0.0.166
User Agent	Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/53.0.2785.143 Safari/537.36
Command Line	/Applications/Google Chrome.app/Contents/MacOS/Google Chrome --flag-switches-begin --flag-switches-end
Executable Path	/Applications/Google Chrome.app/Contents/MacOS/Google Chrome
Profile Path	/Users/taylorperez/Library/Application Support/Google/Chrome/Profile 2
Variations	6a89113b-a7aa8ed
b3888d8d-afba0f91
6345b824-3d47f4f4
7c1bc906-f55a7974
1c752ce9-ca7d8d80
ba3f87da-92cc81ec
f049a919-3f4a17df
31362330-3f4a17df
c70841c8-a2567007
f15c1c09-ca7d8d80
db19c37b-4ad60575
9e5c75f1-c16ec2e6
f5dd6118-3d47f4f4
f79cb77b-3d47f4f4
b7786474-d93a0620
74df3f1-f23d1dea
868bda90-ca7d8d80
4ea303a6-ecbb250e
9736de91-ca7d8d80
dbffab5d-ca7d8d80
867c4c68-3f4a17df
f47ae82a-86f22ee5
3ac60855-486e2a9c
f296190c-477de798
4442aae2-6e597ede
ed1d377-e1cc0f14
75f0f0a0-e1cc0f14
e2b18481-6bdfffe7
e7e71889-e1cc0f14

Platform is Mac, and the Bit-ness is the 64-bit channel. I do have antivirus software on my laptop. 

+ manoranjanr@, can we please try to repro this?

Rechecked this issue on chrome stable version 53.0.2785.143 on Windows 10 and MAC OS 10.11.6. Below are the observations for the same:

Flash Version# 23.0.0.166

Launched the below Web Sites:

1) www.facebook.com - Played some videos
2) http://www.bbc.com/news/world-latin-america-37560228
3) https://www.washingtonpost.com/?reload=true
4) https://twitter.com/search?q=videos&src=typd
5) https://www.washingtonpost.com/video/politics/the-vice-presidential-debate-in-three-minutes/2016/10/04/b2b58e38-8a90-11e6-8cdc-4fbb1973b506_video.html

On Corp machines in a Google network, it is observed that the sites when loads, immediately it plays the videos.

but when the same web sites are tried on a Non corp machine with a Google guest network, it takes time (approximately 10 Minutes) for each site to play the videos. Also the below website never played (Same worked fine on a corp network).

Url: https://www.washingtonpost.com/video/politics/the-vice-presidential-debate-in-three-minutes/2016/10/04/b2b58e38-8a90-11e6-8cdc-4fbb1973b506_video.html

Could this be some thing related to network behavior. 

We could check whether it's a network issue by trying a corp machine but on a Google guest network.

Rechecked this issue on chrome stable version 53.0.2785.143, Flash version Flash Version# 23.0.0.166 on MAC 10.11.6 (corp machine) on a Google guest network.

Launched the below Web Sites:

1) www.facebook.com - Played some videos
2) http://www.bbc.com/news/world-latin-america-37560228
3) https://www.washingtonpost.com/?reload=true
4) https://twitter.com/search?q=videos&src=typd
5) https://www.washingtonpost.com/video/politics/the-vice-presidential-debate-in-three-minutes/2016/10/04/b2b58e38-8a90-11e6-8cdc-4fbb1973b506_video.html

All the above sites played fine without any delay

But Below site never played (Waited for more than 10 minutes):

https://www.washingtonpost.com/opinions/how-trump-absolutely-corrupts-the-gop/2016/10/05/1b218f62-8b27-11e6-875e-2c1bfe943b66_story.html?hpid=hp_no-name_opinion-card-c%3Ahomepage%2Fstory&utm_term=.ceb13bbd2f2f

Same site when switched back to corp network, played immediately.

Please do let us know if any other information is required.

Thanks.!

User experiencing this on GPF: https://productforums.google.com/forum/#!topic/chrome/_lcyvDdlvdQ;context-place=mydiscussions

Yeah, I hear the user's frustration, we have had several issues with Flash recently. I am surprised deletion of the user-data-dir (%USERPROFILE%\AppData\Local\Google\Chrome - more specifically the PepperFlash folder inside that directory) did not work, as that is usually the workaround to the most recent set of symptoms.

Samething here my flash not start i delete pepperflash an reupdate ...noting ... I remove all file of chrome ...noting ... I réinstaller chrome after cleaning ... Noting more ... I dont know what i need to do whit that

Feedback from another user

Version:Version 53.0.2785.143 m (64-bit)
Antivirus: WindowsDefender
Flash folder: 
Manifest.fingerprint
Manifest.json
Pepflashplayer.dll

please remember that I have deleted and reloaded the pepflashplayer.dl' already.

Some more user feedback
1. i can't play any games on my hp laptop because i can't load plugin
2. Same thing and it was working fine until yesterday. Just what is going on? Nothing I did seem to work for me and I'm really getting pissed since there are sites that I need to do my work on that rely on Flash and the plugin  not being loaded despite me having everything updated does not help.

This issue still impacts people and no workaround seems to work.
Is there anything else that we can suggest impacted users ?

https://productforums.google.com/d/msg/chrome/_lcyvDdlvdQ/KAPs3yjaAgAJ

it happends also with the new Chrome 54

@jainabhi... - We've found absolutely no work around at the Chrome Product Forum

This issue still impacts lots of users.

One Top Contributor on Product Forum shared this video (https://www.youtube.com/watch?v=tNpNlzWlJ_s) with workaround to grant pepper flash plugin  "full access" for all users in file's security settings.
This video has 45K views since upload on Aug 3.

Is there anything we can suggest our users ?

99% of my 200+ staff users are on MacOS 10.10.5 network home folders with up to date Chrome 54.0.2840.59 and Flash 23.0.0.185 and we've had to switch to Safari to get Flash sites to play with the NAPPI 23.0.0.185 player, we don't install Adobe's PAPPI plugin we rely on Chrome's built in pepper flash.  Flash 23.0.0.162 works until Chrome auto updates it to 23.0.0.185. and it makes no difference if it's Chrome 53 or 54.

1.  I've tried deleting/replacing affected users' Pepper Flash in ~/Library/Application Support/Google/Chrome/ with my PepperFlash folder that is working for me and while it's not generating the invalid code signature on my system it's not working at all for my users and still giving the "Couldn't load plugin" error.  I deleted their flash and then copied my PepperFlash directory via CLI on our server and reset the ownership permissions after the copy too in addition to outright deleting the PepperFlash folder and letting Chrome rebuild it on launch.

2.  Backing up user bookmarks and starting with an all new profile works until Chrome updates Flash from 23.0.0.162 to 23.0.0.185.

Here is a log entry from an affected user (I obfuscated server and user name) after the Flash 185 update.  This appears when I go to Adobe's about flash page on their site which gives me the "cannot load plugin" error.

10/18/16 1:17:46.168 PM Google Chrome Helper[1272]: Error loading /Network/Servers/server.org/users/username/Library/Application Support/Google/Chrome/PepperFlash/23.0.0.185/PepperFlashPlayer.plugin/Contents/MacOS/PepperFlashPlayer:  dlopen(/Network/Servers/staff.skaggscatholiccenter.org/users/sharonphelps/Library/Application Support/Google/Chrome/PepperFlash/23.0.0.185/PepperFlashPlayer.plugin/Contents/MacOS/PepperFlashPlayer, 262): no suitable image found.  Did find:
	/Network/Servers/server.org/users/username/Library/Application Support/Google/Chrome/PepperFlash/23.0.0.185/PepperFlashPlayer.plugin/Contents/MacOS/PepperFlashPlayer: code signature invalid for '/Network/Servers/staff.skaggscatholiccenter.org/users/sharonphelps/Library/Application Support/Google/Chrome/PepperFlash/23.0.0.185/PepperFlashPlayer.plugin/Contents/MacOS/PepperFlashPlayer'

You can see it's still complaining about "PepperFlashPlayer: code signature invalid"

Hi. I've also run into this annoying issue. I'm forced to use Firefox since chrome won't play anything flash based (in some sites says "can't load plugin" and others like radio players, it just won't load anything).
Tried to uninstall, tried renaming pepflashplayer.dll, tried disabling firewall, tried uninstalling flash from windows, tried also the youtube link provided by jainabhi. Sad to say nothing works. 
Chrome is updated and using 23.0.0.185 player. 

Hope you can figure out a solution, I prefer chrome over Firefox.

If you are having trouble w/ Flash Player, here are the main recommendations:

1.) Clear the Adobe Flash Player component, from your user data directory, and trigger a component update (in chrome://components).

[vuppala18 did a nice job enumerating the directory locations, so I'm just repeating]
Windows 7, 8.1, and 10: C:\Users\<username>\AppData\Local\Google\Chrome\User Data\Default
Mac OS X El Capitan: Users/<username>/Library/Application Support/Google/Chrome/Default
Linux: /home/<username>/.config/google-chrome/default

2.) [If that doesn't work, or you can't find the directory] Install the PPAPI Flash Player from Adobe - http://www.adobe.com/go/chrome/.

@ericbrowning - Could you try running the following command, it would be helpful to see what's failing:

codesign --verify --verbose=6 [/path/to/]PepperFlashPlayer.plugin


Example output:
PepperFlashPlayer.plugin: invalid Info.plist (plist or signature have been modified)
In architecture: x86_64  

@lafo I already had users completely clean out chrome and delete the chrome userdata folder. Nothing seems to help.

@tsrwebgl - What are the contents, in the versioned Flash Player directories (under those user data dirs)?

For example here's what I see:

C:\Users\laforge\AppData\Local\Google\Chrome\User Data\PepperFlash\23.0.0.195>dir

10/14/2016  02:35 PM                66 manifest.fingerprint
10/13/2016  11:16 AM             2,220 manifest.json
10/13/2016  11:16 AM        31,064,768 pepflashplayer.dll
               3 File(s)     31,067,054 bytes
               2 Dir(s)  589,074,391,040 bytes free

C:\Users\laforge\AppData\Local\Google\Chrome\User Data\PepperFlash\23.0.0.195>


Are you (or your users) running any specific AV applications?

@lafo...@chromium.org

This is the output of codesign --verify --verbose=6 ~/Library/Application\ Support/Google/Chrome/PepperFlash/23.0.0.185/PepperFlashPlayer.plugin

/Network/Servers/staff.skaggscatholiccenter.org/users/sharonphelps/Library/Application Support/Google/Chrome/PepperFlash/23.0.0.185/PepperFlashPlayer.plugin: a sealed resource is missing or invalid
file added: /Network/Servers/staff.skaggscatholiccenter.org/users/sharonphelps/Library/Application Support/Google/Chrome/PepperFlash/23.0.0.185/PepperFlashPlayer.plugin/Contents/._Info.plist
file added: /Network/Servers/staff.skaggscatholiccenter.org/users/sharonphelps/Library/Application Support/Google/Chrome/PepperFlash/23.0.0.185/PepperFlashPlayer.plugin/Contents/MacOS/._PepperFlashP

@lafo I'll get back to you on that by close of business tomorrow.

My company is also having this problem!! Really making IT department look bad for pushing users to Chrome due to better security and built in flash updates!

Why are all the support people in the forums and you guys here asking users to run around in circles trying all kind of crazy stuff!?! Uninstall Chrome, delete all of your settings then try installing it yourself! 
There is something really wrong with the Pepper flash plugin and it should not take a Mensa asking people to update drivers and see it works in a closet with the lights off, did you try with the lights on?

Look at the support.. It's really sad for such a large and easily reproducible issue. 

You want logs, remote connection what? Heck give me your email and I'll provide you with my Logmein Rescue user/pass so you can see my machines.

@lafo

Apologies for the delay.  

C:\Users\Jacquie\AppData\Local\Google\Chrome\User Data\PepperFlash\23.0.0.205

10/25/2016  02:19 PM                1 KB manifest.fingerprint
10/24/2016  11:03 AM                3 KB manifest.json
10/24/2016  11:03 AM           17,355 KB pepflashplayer.dll

Rooted around a bit and also found this:
C:\Users\Jacquie\AppData\Local\Google\Chrome SxS\User Data\PepperFlash\23.0.0.181

@lafo that was a direct quote from a user who is having the issue, I just copied and pasted.

Tried installing the latest PAPPI plugin from Adobe.  No change on hundreds of computers.  They still get "Can't Load Plugin" for flash content.  This needs to get fixed.

I have a computer with this problem. Completely uninstalled Chrome and Chrome user data. After re-installing Chrome from scratch there is no Adobe Flash component present.

This directory exists but is completely empty:
C:\Users\username\AppData\Local\Google\Chrome\User Data\PepperFlash

In chrome://components/
Adobe Flash Player - Version: 0.0.0.0

Manually triggering a "Check for update" results in this:
1: Status - component downloading
2: Update ready
3: Status - Component not updated

The component simply won't install no matter what. Even after completely removing any trace of Chrome from the computer's filesystem and registry and re-installing Chrome.

Installing the latest PPAPI from Adobe (23.0.0.205 now shows in chrome://plugins) resolved this issue for me.  Flash plugin is now loading and downloading things appropriately.

Chrome Version 54.0.2840.87 m (64-bit).

As an additional note I am still experiencing the same behavior as Comment 30 was, where the Adobe Flash component will not update from the chrome://components/ page and is showing 0.0.0.0 on that page.  The chrome://plugins/ page still shows the correct version which I installed manually from the Adobe page.

This worked for me in Windows 10:  shift-rightclick on Chrome and Run As Administrator.  Then go to the Chrome://components  and try updating the Flash plugin... success for me!  Good luck!

This might be helpful along the same lines as comment #33.  On the "admin" login of my Macs the flash plugin loads and works.  But then doesn't work with a "standard" user login on the same machine (Yes, even after wiping the chrome profile).  Maybe Chrome has messed things up with flash and it's now loading and requiring admin privs that can't be given with a standard user, hence the "cannot load plugin" message.

Also on Windows 10 Pro x64:
"shift-rightclick on Chrome and Run As Administrator.  Then go to the Chrome://components  and try updating the Flash plugin"
This did not work in my case

"shift-rightclick on Chrome and Run As Administrator.  Then go to the Chrome://components  and try updating the Flash plugin" - Another did not work.

@Comment 35
Updated Flash at Run As Administrator, Check for update in chrome://components. (other  things (previous suggestions here) didn't work anymore, they worked in past, as I already had Flash issue with Chrome and learned how to deal with it, by deleting PepperFlash).

After this update as Administrator, at www.weather2umbrella.com site now it's written "Adobe Flash Player is out of date".
It's not possible to update it as a User (after clicking button "Check for update" in chrome://components:
Adobe Flash Player - Version: 23.0.0.205 
Status - Component not updated)

Before it was written "Couldn't load plugin".
I'm on Win8.1.

Uggh.. Chrome just updated and now I can't play any Flash content. "Could not load plugin".

Flash still works in Vivaldi though.  

I am having this issue on Windows 7 and Windows 10 hosts on a enterprise domain.
Multiple sites have given us issues, internally and externally. 
Removing Chrome, rebooting and then reinstalling the Dev version seemed to fix the issue for all of our users that experienced this weird bug. Perhaps the bug will go away in the next stable release?
https://www.google.co.uk/chrome/browser/beta.html

I should mention the version that we have this working on is 55.0.2883.44 beta (64-bit)
Screenshot attached.

Deleted: 11-11-2016 12-06-05.png 185 KB

	11-11-2016 12-06-05.png 185 KB View Download

Many users encountering "Could not load plugin" are using a user-data-directory on a network drive.

The security concerns with network file systems are great enough that the current thinking of the team is that users (on any OS) using a user-data-dir in a network location will have to install Flash on the local disk by using one of the Adobe-published installers. Unfortunately, this is broken for many users in M54, due to a detail about how Chrome breaks ties between multiple sources of Flash binaries.

There is a CL landed in M55 that is expected to fix any cases where an up-to-date Flash has been installed on the system (i.e. by an Adobe installer, not just by Chrome).

There is mixed support for merging that change into M54 (stable).

"Many users encountering "Could not load plugin" are using a user-data-directory on a network drive."

In my case this is not on a network drive.

I was trying to view South Park, http://southpark.cc.com/clips/egzeyp/bill-clintons-gentlemens-club on Windows 7 Ultimate 64-bit. The machine is NOT on a network.

Google Inc.
Copyright 2016 Google Inc. All rights reserved.
Google Chrome	54.0.2840.99 (Official Build) m (64-bit)
Revision	7eca4ce1e662f12cadaf96c30cd2335fd03e7140-refs/branch-heads/2840@{#830}
OS	Windows 
JavaScript	V8 5.4.500.41
Flash	23.0.0.207
User Agent	Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.99 Safari/537.36
Command Line	"C:\Program Files (x86)\Google\Chrome\Application\chrome.exe" --flag-switches-begin --enable-webgl-draft-extensions --flag-switches-end
Executable Path	C:\Program Files (x86)\Google\Chrome\Application\chrome.exe
Profile Path	C:\Users\roger\AppData\Local\Google\Chrome\User Data\Default
Variations	6a89113b-a7aa8ed
68ebfce2-ca7d8d80
b3888d8d-afba0f91
6345b824-3f4a17df
3095aa95-3f4a17df
7c1bc906-f55a7974
ba3f87da-ca7d8d80
27e74072-186f5907
f15c1c09-ca7d8d80
93731dca-3f4a17df
9e243dd-803f8fc4
9e5c75f1-c16ec2e6
6b121ae7-ca7d8d80
f5dd6118-3d47f4f4
f79cb77b-3d47f4f4
b7786474-d93a0620
74df3f1-803f8fc4
868bda90-ca7d8d80
4ea303a6-3f4a17df
7aa46da5-669a04e0
fe9bec35-186f5907
9736de91-ca7d8d80
dbffab5d-ca7d8d80
867c4c68-ca7d8d80
b2f0086-93053e47
fd029722-3348795
6844d8aa-669a04e0
f47ae82a-86f22ee5
3ac60855-486e2a9c
f296190c-a2200d3b
4442aae2-e1cc0f14
ed1d377-e1cc0f14
75f0f0a0-6bdfffe7
e2b18481-bca011b3
e7e71889-4ad60575
828a5926-ca7d8d80
Compiler	MSVC 2015 (PGO)

Edit above comment to add: Contents of Pepperflash folder:

manifest.fingerprint
manifest.json

Mcrog try out the Beta and let us know how you get on?!
https://www.google.co.uk/chrome/browser/beta.html

SOLUTION ALERT!!!

https://productforums.google.com/d/msg/chrome/_lcyvDdlvdQ/ui2xO3MbAwAJ

"SOLUTION ALERT!!! https://productforums.google.com/d/msg/chrome/_lcyvDdlvdQ/ui2xO3MbAwAJ"

This did not work for me. The folder already has all permissions set correctly.

The "solution alert" from comment #47 didn't work for me either and I have
several hundred accounts.

I fixed the issue on my Linux, if you use Linux with Chrome54, and your .config/google-chrome/PepperFlash is empty, you can try to 

1. Open chrome://components/
2. Click "Check for updates" below "Adobe flash player".

(If you from Mainland China, you may have to use whatever proxy tool(like proxychains) to proxy Chrome to let step 2 to work properly)

Hope this is helpful to someone using Linux.

"1. Open chrome://components/
2. Click "Check for updates" below "Adobe flash player"."

This was already suggested before but doesn't work for everyone. Look at Comment 30, 32, 35 and 36 above for several examples.

Why was the pepperflash location changed out of the 'program files' install folder and into each user's profile folder? We had Chrome happily working in a terminal services environment for 2000 users, and as of Chrome 54, Flash is completely broken. We store profiles on network shares, and Flash has long been known to choke on network shares. 

This change is a breaking change for anyone who uses Chrome in an enterprise terminal services environment. If you're trying to increase user adoption of Internet Explorer or Firefix, you're on the right track.

For Enterprise deployments using network shares, we recommend disabling the component updater(1) and instead deploying the Flash Player MSI/ Package directly from Adobe(2).

(1) - https://www.chromium.org/administrators/policy-list-3#ComponentUpdatesEnabled
(2) - https://support.google.com/chrome/a/answer/7084871

THANK YOU COMMENT 36!
This FINALLY did the trick for me! I can't believe it. I've tried EVERYTHING!

"shift-rightclick on Chrome and Run As Administrator.  Then go to the Chrome://components  and try updating the Flash plugin" - Another did not work.

"For Enterprise deployments using network shares, we recommend disabling the component updater(1) and instead deploying the Flash Player MSI/ Package directly from Adobe(2)"

I'm not in an Enterprise deployment with network shares.

FIX: To resolve this I did the following:

1. Exit Chrome by clicking the three dots in the upper right, and clicking exit
2. Go to %localappdata%\Google\Chrome\User Data, in Windows File Explorer
3. Rename folder "PepperFlash" to "PepperFlash.old"
4. Shift+Right Click Chrome icon, and select "Run as Administrator"
5. In Chrome's address bar go to chrome://components
6. Find "Adobe Flash" It should say you are on version 0.0.0.0.
7. Click "Check for Update" and wait for it to update.
8. In Chrome's address bar go to chrome://restart
9. Test it somewhere you previously had issues

This worked for me on 3 different machines, but, as always, YMMV.

I tried a few variations of fixes found on diff sites for this. I didn't try the run as admin fixes(like comment 57 above), bc I fixed a diff way. Its more complicated, but worked for me so wanted to share.

I uninstalled chrome, deleted the pepperflash folder in appdata, reinstalled chrome. 

The following steps from above did not work for me, since the peperflash folder remained empty no matter what I did:
5. In Chrome's address bar go to chrome://components
6. Find "Adobe Flash" It should say you are on version 0.0.0.0.
7. Click "Check for Update" and wait for it to update.

So instead, I went to http://www.adobe.com/software/flash/about/ and it loaded the newest flash automatically! Fixed!

So to be a bit more precise, i did steps 1-3 from comment 57

then uninstalled/reinstalled chrome (probably not necessary)

then I went to http://www.adobe.com/software/flash/about/ and it loaded the newest flash automatically! Fixed!

Weird Chrome wasn't able to redownload on it's own, but glad that helped ya!

Google Chrome	55.0.2883.75 (Official Build) m (64-bit)
Revision	451c239c3b0722dc867b0f75839b959f729b756a-refs/branch-heads/2883@{#698}
OS	Windows 
JavaScript	V8 5.5.372.29
Flash	23.0.0.185
User Agent	Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/55.0.2883.75 Safari/537.36
Command Line	"C:\Program Files (x86)\Google\Chrome\Application\chrome.exe" --flag-switches-begin --flag-switches-end

Version of Flash this is installed according to Windows is 23.0.0.207, Chrome is the only browser on this computer that has this flash issue.

Uses Ninite Pro to keep software up to date.

Ran the repair that Ninite has, it didn't fix it.   Manually ran the Adobe flash update, it worked.

All the fixes that involve redownloading Flash (like Firedrake's steps) work for a short time, then the problem comes back. It's like Chrome waits 5 minutes then does an automatic update of some sort that reverts to a non-working state.

We have been having this issue in our 22k user enterprise environment. User profiles are stored locally, not on the network. We are hoping to avoid using the Adobe .msi files as that becomes an additional piece of software that we must patch on a regular basis.

All of the fixes offered above have not worked in our environment. However uninstalling Symantec Endpoint Protection resolved the issue in 100% of cases. Reinstalling SEP re-introduced the issue.

We have opened a case with Symantec.

Symantec has confirmed that this is a known issue. Below is their response to our case.

After reviewing this case and the available data (primarily the provided WPP logs) I have found that this is a known-issue with the SEP 12.1 and SEP 14 products. SEP is attempting to obtain a hash of the Adobe Flash Player file 'pepflashplayer.dll'; however, during the hash operation, Chrome is attempting to move the file from a temporary folder (where SEP is performing the hash) to Chrome's plugin folder; since SEP has a lock on the file, Chrome's move operation fails and the plugin update process aborts.

Symantec has identified a fix for this issue and is planning on including a resolution in the next release of SEP 12.1 and SEP 14, both due out early next year.

It is possible to work around this issue by disabling deferred scanning for AutoProtect; however, this is not generally recommended in production unless absolutely needed, as it disables scan throttling based on I/O activity.

For more information on disabling deferred scanning, please see the following KB document:

How to disable deferred scanning in Auto-Protect for Symantec Endpoint Protection
https://support.symantec.com/en_US/article.TECH224108.html

It is also possible to work around the issue by temporarily disabling SEP; however, this is a potential security issue, as you will be temporarily disabling the product from being able to scan files.

Is it possibly a similar issue with Microsoft Defender? I have Win 10 and no 3rd party AV installed. It's weird how it works initially, and then as soon as Chrome updates, it stops working.

Re: #64 & #65, thanks for sharing these findings.

We've seen similar issues with other AV (as far as I know, not Microsoft Defender, though). If I landed a speculative workaround in Canary and you can reliably reproduce this issue, would you be willing to try the Canary build to confirm whether or not the workaround is effective?

Sure. I already have Canary installed on the affected computer. I can test.

Has Symantec provided a date that the fix will go out?

I am experiencing this, corporate environment with SEP 12.x.  Disabling SEP locally (right click->Disable Symantec Endpoint Protection) doesn't seem to work for me.  If I obtain the files from a machine that has them installed, is there a way to copy them to an existing installation to get the Flash Chrome components updated manually?

I was able to somewhat manually update this by taking a copy of the PepperFlash folder from my home system running Chrome 55 in the users profile and copying it to a work system with the following steps.  YMMV, but hopefully this helps someone.

1.	Close Chrome.
2.	Go to c:\users\<username>\AppData\LocalGoogle\Chrome\User Data and find and delete the PepperFlash folder.
3.	Copy the PepperFlash folder from a working updated system in the same source folder and place it into the User Data director where you just deleted the old one.
4.	Start Chrome
5.	In the address bar, type chrome://components
6.	Find the Adobe Flash Player, it will say Version: 0.0.0.0, Status New. Hit the Check for update button.
7.	The status will change a couple of times and end up with Status – Component updated and the version will be at 24.0.0.186.

Comment 48 -> this is something that finally solved my problem!
Thank you!

Re: Comment 67 - I can reliably reproduce the issue. I would be happy to test anything you need.

Re: Comment 69 - We were never given a release date schedule, but I believe it's due out this month or next.

This affects us, and as a result, our users are unable to perform their required training for our organization unless we install the standalone Flash client, which requires us to install and manage it on 200+ computers.

So, you know, thanks for that.

We experienced the same Flash updating issue, and the workaround described in Comment 71 worked for us.  We just upgraded to SEP 14.0.1904.0000, and the issue no longer exists.

Here is the latest update from SEP:

"I'm still monitoring our internal defect tracking system for updates. After discussion with our engineering release team, it has been determined that Symantec Endpoint Protection 12.1 will not contain a fix for this issue. The fix will only be available in SEP 14.0 MP1, which will be released later this month (February, 2017). It will be a full build and will follow the normal migration process for SEP (unchanged on the client side in 14.0 compared to 12.1). The fix cannot be delivered via LiveUpdate.

I'm continuing to watch for updates as they become available from development and will let you know once SEP 14.0 MP1 is available."

It appears SEP 14.0.0 MP1 came out on 2/18/2017 and now contains a fix for this.

Chrome Adobe Flash component fails to update with SMC started
FIX ID: 4050141
Symptom: Chrome fails to update the Adobe Flash component with the Symantec Management Client (SMC) enabled.
Solution: Corrected an issue where Symantec Endpoint Protection blocked the Chrome Flash component update.

Based on last few comments, I'm closing this bug as not reproducible.