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Issue 640844 Blocking the load of cross-origin, parser-blocking scripts inserted via document.write for users on 2G
Starred by 14 users Project Member Reported by kenjibaheux@chromium.org, Aug 25 2016 Back to list
Status: Fixed
Owner:
Closed: Apr 5
Cc:
Components:
EstimatedDays: ----
NextAction: ----
OS: All
Pri: 2
Type: Launch-OWP
Launch-Accessibility: NA
Launch-Legal: Yes
Launch-M-Approved: ----
Launch-M-Target: ----
Launch-Privacy: Yes
Launch-Security: Yes
Launch-Status: ----
Launch-Test: Yes
Launch-UI: NA


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Change description:
For users on slow connections such as 2G, the performance penalty from third-party scripts loaded via document.write is often so severe as to delay display of main page content for tens of seconds. This feature will block the load of cross-origin, parser-blocking scripts inserted via document.write in case of an HTTP cache miss for users on a 2G connection. The feature will only be applicable to such scripts in the main frame.

Changes to API surface:
See the draft spec of the intervention:
 https://github.com/WICG/interventions/issues/17#issuecomment-238477265

Links:
Public standards discussion: <https://github.com/WICG/interventions/issues/17>

Support in other browsers:
Internet Explorer: no
Firefox: no
Safari: no

*Make sure to fill in any labels with a -?, including all OSes this change
affects. Feel free to leave other labels at the defaults.

 
Labels: -M-54 M-55
Aiming at Chrome 55.
Blocking: 640846
Blockedon: 621520 635743 602644 611813 649082 639401
Blockedon: 658983
Blockedon: 668029
Blockedon: -668029
I'm shopping on Real Madrid Store and getting this error. I'm on a 105mb connection and I'm pretty sure RM isn't serving off of a 2G connection, so what's up?

basket:16 A Parser-blocking, cross-origin script, http://e.monetate.net/js/2/a-3048d11e/p/realmadridshop.com/entry.js, is invoked via document.write. This may be blocked by the browser if the device has poor network connectivity. See https://www.chromestatus.com/feature/5718547946799104 for more details.
Comment 8 by jkarlin@google.com, Dec 15 2016
#7, it's not blocking the request, just giving a warning that it would be blocked under the right circumstances. This is to give developers a heads up about the issue.
Have had difficulty on every shopping website I have been on today.

tas:190 A Parser-blocking, cross-origin script, http://www.google-analytics.com/ga.js, is invoked via document.write. This may be blocked by the browser if the device has poor network connectivity. See https://www.chromestatus.com/feature/5718547946799104 for more details.
OR:
2satelliteLib-ef48825….js:10 A Parser-blocking, cross-origin script, http://assets.adobedtm.com/3c42c63b493c1af35d8caf2270583ef8ca5bdce4/mbox-contents-e848cae1f237cd42fb137c1796f98b33eafc3c2a.js, is invoked via document.write. This may be blocked by the browser if the device has poor network connectivity. See https://www.chromestatus.com/feature/5718547946799104 for more details.
loadScriptSync @ satelliteLib-ef48825….js:10
load @ satelliteLib-ef48825….js:11
initialize @ satelliteLib-ef48825….js:11
endPLPhase @ satelliteLib-ef48825….js:11
E.firePageLoadEvent @ satelliteLib-ef48825….js:10
E.init @ satelliteLib-ef48825….js:10
(anonymous) @ satelliteLib-ef48825….js:12
(anonymous) @ satelliteLib-ef48825….js:12
satelliteLib-ef48825….js:10 A Parser-blocking, cross-origin script, http://assets.adobedtm.com/3c42c63b493c1af35d8caf2270583ef8ca5bdce4/scripts/satellite-57fe788d64746d4cce00243c.js, is invoked via document.write. This may be blocked by the browser if the device has poor network connectivity. See https://www.chromestatus.com/feature/5718547946799104 for more details.
loadScriptSync @ satelliteLib-ef48825….js:10
loadBlockingScript @ satelliteLib-ef48825….js:11
(anonymous) @ satelliteLib-ef48825….js:11
each @ satelliteLib-ef48825….js:10
(anonymous) @ satelliteLib-ef48825….js:11
(anonymous) @ satelliteLib-ef48825….js:10
$loadBlockingScript @ satelliteLib-ef48825….js:11
triggerCommand @ satelliteLib-ef48825….js:10
a @ satelliteLib-ef48825….js:10
E.execute @ satelliteLib-ef48825….js:10
E.fireRule @ satelliteLib-ef48825….js:10
E.firePageLoadEvent @ satelliteLib-ef48825….js:10
E.init @ satelliteLib-ef48825….js:10
(anonymous) @ satelliteLib-ef48825….js:12
(anonymous) @ satelliteLib-ef48825….js:12
2mbox-contents-e848cae….js:3 A Parser-blocking, cross-origin script, http://vitacost.tt.omtrdc.net/m2/vitacost/mbox/standard?mboxHost=www.vitaco…t.com%2F%3F%26csrc%3DEM-APIWELC20161228%3Acta&mboxReferrer=&mboxVersion=41, is invoked via document.write. This may be blocked by the browser if the device has poor network connectivity. See https://www.chromestatus.com/feature/5718547946799104 for more details.
mboxStandardFetcher.fetch @ mbox-contents-e848cae….js:3
mbox.load @ mbox-contents-e848cae….js:3
mboxCreate @ mbox-contents-e848cae….js:3
mboxCreate @ mbox-contents-e848cae….js:4
(anonymous) @ ?&csrc=EM-APIWELC20161228:cta:51
2mbox-contents-e848cae….js:3 A Parser-blocking, cross-origin script, http://vitacost.tt.omtrdc.net/m2/vitacost/mbox/standard?mboxHost=www.vitaco…t.com%2F%3F%26csrc%3DEM-APIWELC20161228%3Acta&mboxReferrer=&mboxVersion=41, is invoked via document.write. This may be blocked by the browser if the device has poor network connectivity. See https://www.chromestatus.com/feature/5718547946799104 for more details.
mboxStandardFetcher.fetch @ mbox-contents-e848cae….js:3
mbox.load @ mbox-contents-e848cae….js:3
mboxCreate @ mbox-contents-e848cae….js:3
mboxCreate @ mbox-contents-e848cae….js:4
(anonymous) @ ?&csrc=EM-APIWELC20161228:cta:1870
2mbox-contents-e848cae….js:3 A Parser-blocking, cross-origin script, http://vitacost.tt.omtrdc.net/m2/vitacost/mbox/standard?mboxHost=www.vitaco…t.com%2F%3F%26csrc%3DEM-APIWELC20161228%3Acta&mboxReferrer=&mboxVersion=41, is invoked via document.write. This may be blocked by the browser if the device has poor network connectivity. See https://www.chromestatus.com/feature/5718547946799104 for more details.
mboxStandardFetcher.fetch @ mbox-contents-e848cae….js:3
2mbox-contents-e848cae….js:3 A Parser-blocking, cross-origin script, http://vitacost.tt.omtrdc.net/m2/vitacost/mbox/standard?mboxHost=www.vitaco…t.com%2F%3F%26csrc%3DEM-APIWELC20161228%3Acta&mboxReferrer=&mboxVersion=41, is invoked via document.write. This may be blocked by the browser if the device has poor network connectivity. See https://www.chromestatus.com/feature/5718547946799104 for more details.
mboxStandardFetcher.fetch @ mbox-contents-e848cae….js:3
2mbox-contents-e848cae….js:3 A Parser-blocking, cross-origin script, http://vitacost.tt.omtrdc.net/m2/vitacost/mbox/standard?mboxHost=www.vitaco…t.com%2F%3F%26csrc%3DEM-APIWELC20161228%3Acta&mboxReferrer=&mboxVersion=41, is invoked via document.write. This may be blocked by the browser if the device has poor network connectivity. See https://www.chromestatus.com/feature/5718547946799104 for more details.
mboxStandardFetcher.fetch @ mbox-contents-e848cae….js:3
2mbox-contents-e848cae….js:3 A Parser-blocking, cross-origin script, http://vitacost.tt.omtrdc.net/m2/vitacost/mbox/standard?mboxHost=www.vitaco…t.com%2F%3F%26csrc%3DEM-APIWELC20161228%3Acta&mboxReferrer=&mboxVersion=41, is invoked via document.write. This may be blocked by the browser if the device has poor network connectivity. See https://www.chromestatus.com/feature/5718547946799104 for more details.
mboxStandardFetcher.fetch @ mbox-contents-e848cae….js:3
2mbox-contents-e848cae….js:3 A Parser-blocking, cross-origin script, http://vitacost.tt.omtrdc.net/m2/vitacost/mbox/standard?mboxHost=www.vitaco…t.com%2F%3F%26csrc%3DEM-APIWELC20161228%3Acta&mboxReferrer=&mboxVersion=41, is invoked via document.write. This may be blocked by the browser if the device has poor network connectivity. See https://www.chromestatus.com/feature/5718547946799104 for more details.
mboxStandardFetcher.fetch @ mbox-contents-e848cae….js:3
vitacost.custom.min.js:15 Uncaught TypeError: Cannot read property 'toString' of undefined
    at String.<anonymous> (http://www.vitacost.com/res/(v16.5.6)/javascripts/vitacost.custom.min.js:15:294)
    at Function.each (http://www.vitacost.com/res/(v16.5.6)/javascripts/vitacost.min.js:14:16345)
    at Object.init (http://www.vitacost.com/res/(v16.5.6)/javascripts/vitacost.custom.min.js:15:187)
    at HTMLDocument.<anonymous> (http://www.vitacost.com/res/(v16.5.6)/javascripts/vitacost.custom.min.js:15:6101)
    at a (http://www.vitacost.com/res/(v16.5.6)/javascripts/vitacost.min.js:25:18342)
    at Object.fireWith [as resolveWith] (http://www.vitacost.com/res/(v16.5.6)/javascripts/vitacost.min.js:25:19146)
    at Function.ready (http://www.vitacost.com/res/(v16.5.6)/javascripts/vitacost.min.js:14:14259)
    at HTMLDocument.h (http://www.vitacost.com/res/(v16.5.6)/javascripts/vitacost.min.js:14:11629)
http://static.criteo.net/js/ld/ld.js Failed to load resource: net::ERR_BLOCKED_BY_CLIENT
http://bat.bing.com/bat.js Failed to load resource: net::ERR_BLOCKED_BY_CLIENT
Blockedon: 678124
Blockedon: -678124
This seems to be blocking cross-site scripts from a desktop Chrome on a PC with a perfectly solid internet connection. It's breaking a few wikia sites.

https://www.chromestatus.com/feature/5718547946799104 says "enabled by default". How do I disable it? I searched chrome://flags for "cross-site" and "intervention" but couldn't find the flag.
Thanks Jason for the report. Can you provide a link to example URLs that are broken?

What we have typically observed in cases like this is that the warning indicating that a resource would be blocked on slow connections is displayed, but that resource isn't actually blocked.

Separately, there exists some other issue on the page - perhaps the site pushed code that includes a bug that's causing the issue, or perhaps the user experiencing the issue has an extension such as an ad blocker installed that is breaking the page in some way. It's this latter issue, not the doc.write intervention, that's causing the breakage.

I'm happy to take a look at some example URLs to see if we can figure out what's going on here. Can you send URLs to one or more wikia pages where you are seeing the issue? Can you also include the full output you see in the devtools console, both for this intervention as well as all other messages displayed while on the page?

Thanks,
Bryan
http://simcity.wikia.com/wiki/List_of_items_in_SimCity_BuildIt for example, works fine on Firefox. Chrome 55 fails to load the page, however. The page loads but some JavaScript-y areas get stuck on "loading" (e.g. when attempting to edit, click "My Account", and some area on the right side bar), giving the slow connection cross-site script intervention messages.

The wikia page is therefore not usuable on Chrome aside from being able to read it.


I'm not really sure how to properly copy and paste from the log, here are the results of "save as" from the context menu for the previous link:

List_of_items_in_SimCity_BuildIt?veaction=edit:86 A Parser-blocking, cross-origin script, http://a.wikia-beacon.com/__track/view?cb=1485257920&c=1541&lc=en&lid=75&x=…4780&s=oasis&beacon=xv4Fh703YH&n=0&r=&rand=1485280474157&beacon=xv4Fh703YH, is invoked via document.write. This may be blocked by the browser if the device has poor network connectivity. See https://www.chromestatus.com/feature/5718547946799104 for more details.
(anonymous) @ List_of_items_in_SimCity_BuildIt?veaction=edit:86
(anonymous) @ List_of_items_in_SimCity_BuildIt?veaction=edit:87
List_of_items_in_SimCity_BuildIt?veaction=edit:86 A Parser-blocking, cross-origin script, http://a.wikia-beacon.com/__track/view?cb=1485257920&c=1541&lc=en&lid=75&x=…4780&s=oasis&beacon=xv4Fh703YH&n=0&r=&rand=1485280474157&beacon=xv4Fh703YH, is invoked via document.write. This may be blocked by the browser if the device has poor network connectivity. See https://www.chromestatus.com/feature/5718547946799104 for more details.
(anonymous) @ List_of_items_in_SimCity_BuildIt?veaction=edit:86
(anonymous) @ List_of_items_in_SimCity_BuildIt?veaction=edit:87
abtesting,oasis_blocking,universal_analytics_js,adengine2_tracking_js,optimizely_blocking_js,qualar…:2 Wikia.AbTest.init(): Loading external configuration
abtesting,oasis_blocking,universal_analytics_js,adengine2_tracking_js,optimizely_blocking_js,qualar…:30 A Parser-blocking, cross-origin script, http://api.wikia.nocookie.net/__cb1485257920/wikia.php?controller=AbTesting…rnalData&ids=RECIRCULATION_MIX.415.326,PAGE_HEADER_RDPS_EXPERIMENT.408.321, is invoked via document.write. This may be blocked by the browser if the device has poor network connectivity. See https://www.chromestatus.com/feature/5718547946799104 for more details.
(anonymous) @ abtesting,oasis_blocking,universal_analytics_js,adengine2_tracking_js,optimizely_blocking_js,qualar…:30
(anonymous) @ abtesting,oasis_blocking,universal_analytics_js,adengine2_tracking_js,optimizely_blocking_js,qualar…:30
(anonymous) @ abtesting,oasis_blocking,universal_analytics_js,adengine2_tracking_js,optimizely_blocking_js,qualar…:30
abtesting,oasis_blocking,universal_analytics_js,adengine2_tracking_js,optimizely_blocking_js,qualar…:30 A Parser-blocking, cross-origin script, http://api.wikia.nocookie.net/__cb1485257920/wikia.php?controller=AbTesting…rnalData&ids=RECIRCULATION_MIX.415.326,PAGE_HEADER_RDPS_EXPERIMENT.408.321, is invoked via document.write. This may be blocked by the browser if the device has poor network connectivity. See https://www.chromestatus.com/feature/5718547946799104 for more details.
(anonymous) @ abtesting,oasis_blocking,universal_analytics_js,adengine2_tracking_js,optimizely_blocking_js,qualar…:30
(anonymous) @ abtesting,oasis_blocking,universal_analytics_js,adengine2_tracking_js,optimizely_blocking_js,qualar…:30
(anonymous) @ abtesting,oasis_blocking,universal_analytics_js,adengine2_tracking_js,optimizely_blocking_js,qualar…:30
List_of_items_in_SimCity_BuildIt?veaction=edit:2238 GET http://slot1.images.wikia.nocookie.net/__am/1485257920/groups/-/oasis_share…on_liftigniter_tracker,recirculation_js,toc_js,qualaroo_js,relatedpages_js net::ERR_BLOCKED_BY_CLIENT
abtesting,oasis_blocking,universal_analytics_js,adengine2_tracking_js,optimizely_blocking_js,qualar…:2 Wikia.AbTest.init(): Received external configuration
startup:25 A Parser-blocking, cross-origin script, http://slot1.images3.wikia.nocookie.net/__load/-/debug%3Dfalse%26lang%3Den%…ts%26skin%3Doasis%26version%3D1485257920-20170123T184500Z/jquery,mediawiki, is invoked via document.write. This may be blocked by the browser if the device has poor network connectivity. See https://www.chromestatus.com/feature/5718547946799104 for more details.
(anonymous) @ startup:25
startup:25 A Parser-blocking, cross-origin script, http://slot1.images3.wikia.nocookie.net/__load/-/debug%3Dfalse%26lang%3Den%…ts%26skin%3Doasis%26version%3D1485257920-20170123T184500Z/jquery,mediawiki, is invoked via document.write. This may be blocked by the browser if the device has poor network connectivity. See https://www.chromestatus.com/feature/5718547946799104 for more details.
(anonymous) @ startup:25
jquery,mediawiki:152 A Parser-blocking, cross-origin script, http://slot1.images.wikia.nocookie.net/__load/-/debug%3Dfalse%26lang%3Den%2…Locale,history,importScript,loader,mw,nirvana,throbber,thumbnailer,tracker, is invoked via document.write. This may be blocked by the browser if the device has poor network connectivity. See https://www.chromestatus.com/feature/5718547946799104 for more details.
addScript @ jquery,mediawiki:152
doRequest @ jquery,mediawiki:156
work @ jquery,mediawiki:158
request @ jquery,mediawiki:154
load @ jquery,mediawiki:162
(anonymous) @ List_of_items_in_SimCity_BuildIt?veaction=edit:2237
jquery,mediawiki:152 A Parser-blocking, cross-origin script, http://slot1.images.wikia.nocookie.net/__load/-/debug%3Dfalse%26lang%3Den%2…Locale,history,importScript,loader,mw,nirvana,throbber,thumbnailer,tracker, is invoked via document.write. This may be blocked by the browser if the device has poor network connectivity. See https://www.chromestatus.com/feature/5718547946799104 for more details.
addScript @ jquery,mediawiki:152
doRequest @ jquery,mediawiki:156
work @ jquery,mediawiki:158
request @ jquery,mediawiki:154
load @ jquery,mediawiki:162
(anonymous) @ List_of_items_in_SimCity_BuildIt?veaction=edit:2237
ext.bannerNotifications,cookiePolicyMessages,userLogin|ext.visualEditor.track,ve|ext.visualEditor.w…:4 Uncaught TypeError: $.getSassCommonURL is not a function
    at getTarget (ext.bannerNotifications,cookiePolicyMessages,userLogin|ext.visualEditor.track,ve|ext.visualEditor.w…:4)
    at HTMLDocument.<anonymous> (ext.bannerNotifications,cookiePolicyMessages,userLogin|ext.visualEditor.track,ve|ext.visualEditor.w…:9)
    at fire (jquery,mediawiki:12)
    at Object.fireWith [as resolveWith] (jquery,mediawiki:14)
    at Function.ready (jquery,mediawiki:6)
    at HTMLDocument.DOMContentLoaded (jquery,mediawiki:2)
getTarget @ ext.bannerNotifications,cookiePolicyMessages,userLogin|ext.visualEditor.track,ve|ext.visualEditor.w…:4
(anonymous) @ ext.bannerNotifications,cookiePolicyMessages,userLogin|ext.visualEditor.track,ve|ext.visualEditor.w…:9
fire @ jquery,mediawiki:12
fireWith @ jquery,mediawiki:14
ready @ jquery,mediawiki:6
DOMContentLoaded @ jquery,mediawiki:2
amd|wikia.tracker.stub,stub|wikia.abTest,cache,cookies,document,geo,instantGlobals,localStorage,loc…:3 Uncaught Module BannerNotification is not defined.
(anonymous) @ amd|wikia.tracker.stub,stub|wikia.abTest,cache,cookies,document,geo,instantGlobals,localStorage,loc…:3
amd|wikia.tracker.stub,stub|wikia.abTest,cache,cookies,document,geo,instantGlobals,localStorage,loc…:3 Uncaught Module BannerNotification is not defined.
(anonymous) @ amd|wikia.tracker.stub,stub|wikia.abTest,cache,cookies,document,geo,instantGlobals,localStorage,loc…:3
amd|wikia.tracker.stub,stub|wikia.abTest,cache,cookies,document,geo,instantGlobals,localStorage,loc…:3 Uncaught Module wikia.ui.factory is not defined.
(anonymous) @ amd|wikia.tracker.stub,stub|wikia.abTest,cache,cookies,document,geo,instantGlobals,localStorage,loc…:3
amd|wikia.tracker.stub,stub|wikia.abTest,cache,cookies,document,geo,instantGlobals,localStorage,loc…:3 Uncaught Module wikia.mustache is not defined.
(anonymous) @ amd|wikia.tracker.stub,stub|wikia.abTest,cache,cookies,document,geo,instantGlobals,localStorage,loc…:3
amd|wikia.tracker.stub,stub|wikia.abTest,cache,cookies,document,geo,instantGlobals,localStorage,loc…:3 Uncaught Module wikia.mustache is not defined.
(anonymous) @ amd|wikia.tracker.stub,stub|wikia.abTest,cache,cookies,document,geo,instantGlobals,localStorage,loc…:3

Thanks! I see

List_of_items_in_SimCity_BuildIt?veaction=edit:2238 GET http://slot1.images.wikia.nocookie.net/__am/1485257920/groups/-/oasis_share…on_liftigniter_tracker,recirculation_js,toc_js,qualaroo_js,relatedpages_js net::ERR_BLOCKED_BY_CLIENT

Messages like this are usually displayed due to an adblocker or similar extension. It may explain the breakage you are experiencing. Do you have any extensions installed that might be blocking the load of this resource? if you open the same page in an incognito window, for example, or with extensions disabled, does the site work ok for you?
I had AdBlock disabled but that didn't help. In an incognito window it does help. It must be an extension. I can figure it out from here and sorry for the noise. Let me know if you'd like me to delete my comments here to keep the page clean.
And thanks for your quick help.
No problem, thanks for debugging! I think leaving these comments is valuable as it may help other devs who find this bug to debug any issues they are seeing. Thanks again!
Blockedon: 684831
Blockedon: 685009
When I attempt to log into  southwest.com - the post fails with 302

Request URL:https://www.southwest.com/flight/login?loginEntryPoint=GLOBAL_NAV_LOGIN
Request Method:POST
Status Code:302 Moved Temporarily
Remote Address:23.222.75.177:443

The console reads 
A Parser-blocking, cross-origin script, https://cdn.tt.omtrdc.net/cdn/target.js, is invoked via document.write. This may be blocked by the browser if the device has poor network connectivity. See https://www.chromestatus.com/feature/5718547946799104 for more details.
df @ mbox.js:53
(anonymous) @ mbox.js:53
mbox.js:53 A Parser-blocking, cross-origin script, https://southwestairlines.tt.omtrdc.net/m2/southwestairlines/mbox/ajax?mbox…enance.html&mboxReferrer=https%3A%2F%2Fwww.southwest.com%2F&mboxVersion=58, is invoked via document.write. This may be blocked by the browser if the device has poor network connectivity. See https://www.chromestatus.com/feature/5718547946799104 for more details.

I am flummoxed because it is on a fast connection. It seems like whatever is deciding the connection is slow is not quite right?


Thanks for these details! The message about 'a parser blocking...' is just a warning, indicating that the fetch may be blocked in other cases, but wasn't necessarily blocked in this case. If the resource was blocked, you'd see an additional console message with error ERR_CACHE_MISS.

So in this case, the 302 issue seems unrelated to this warning.

Can you try visiting the same URL in an incognito window to see if it works there?
ignognito got the same result - But an additional failure message

A Parser-blocking, cross-origin script, https://cdn.tt.omtrdc.net/cdn/target.js, is invoked via document.write. This may be blocked by the browser if the device has poor network connectivity. See https://www.chromestatus.com/feature/5718547946799104 for more details.
df @ mbox.js:53
mbox.js:53 A Parser-blocking, cross-origin script, https://southwestairlines.tt.omtrdc.net/m2/southwestairlines/mbox/ajax?mbox…enance.html&mboxReferrer=https%3A%2F%2Fwww.southwest.com%2F&mboxVersion=58, is invoked via document.write. This may be blocked by the browser if the device has poor network connectivity. See https://www.chromestatus.com/feature/5718547946799104 for more details.
fetch @ mbox.js:53
Failed to create temp file 18 : It was determined that certain files are unsafe for access within a Web application, or that too many calls are being made on file resources.


I don't know if this is relevant -  but "Upgrade-Insecure-Requests:1" sounds ominous to me

Accept:text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
Accept-Encoding:gzip, deflate, br
Accept-Language:en-US,en;q=0.8
Cache-Control:max-age=0
Connection:keep-alive
Content-Length:50
Content-Type:application/x-www-form-urlencoded
Cookie:JSESSIONID=6D8CE140CAA4A7B2C232DFA49AE572F8; AccountBarCookie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s_wr=d0b62960-5ea6-40fc-8586-b093c6a19f78; AMCV_65D316D751E563EC0A490D4C%40AdobeOrg=283337926%7CMCIDTS%7C17196%7CMCMID%7C43597457647377365087490941918234462815%7CMCAAMLH-1486334762%7C7%7CMCAAMB-1486334762%7CNRX38WO0n5BH8Th-nqAG_A%7CMCAID%7CNONE; akavpau_prod_fullsite=1485730154~id=b23f13f1d9fa1eb358aa2d3411a15c0e; mbox=session#1485729961651-365036#1485732015|PC#1485729961651-365036.20_65#1490914155|check#true#1485730215; s_cc=true; s_sq=swaprod%3D%2526pid%253DHP%25253ASWA%25253ASouthwest%252520Homepage%2526pidt%253D1%2526oid%253DLog%252520in%2526oidt%253D3%2526ot%253DSUBMIT; forceLoyaltyLoginCookie=1
Host:www.southwest.com
Origin:https://www.southwest.com
Referer:https://www.southwest.com/
Upgrade-Insecure-Requests:1
User-Agent:Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/56.0.2924.76 Safari/537.36
Ah, thank you. I'm not sure what may be going on in this case. A final check we can do is to force disable the document.write blocking feature. I don't think it's causing this issue but if it still happens with the feature force disabled, we can know for certain that it's not this feature causing the issue.

Can you navigate to chrome://flags/#disallow-doc-written-script-loads (need to copy/paste this URL into the browser) and choose 'Disabled' for 'Block scripts loaded via document.write'?

Note that you will still see the console messages warning about the issue with this disabled, but the behavior to block will be force disabled. If you continue to see the issue after force disabling, it rules out the doc.write feature being the cause.

Thanks,
Bryan
I should ask - what does happen when you attempt to visit the site? Does the load just hang forever? Or does the page load but not work properly? Or something else?
also - I am 


Request URL:https://www.southwest.com/flight/login?loginEntryPoint=GLOBAL_NAV_LOGIN
Request Method:POST
Status Code:302 Moved Temporarily
Remote Address:23.222.75.177:443


the tracert to that site took a long time?

C:\Windows\System32>tracert 23.222.75.177

Tracing route to a23-222-75-177.deploy.static.akamaitechnologies.com [23.222.75.177]
over a maximum of 30 hops:

  1     1 ms     1 ms     1 ms  192.168.1.1
  2     1 ms     1 ms     1 ms  192.168.0.1
  3    11 ms    11 ms    11 ms  d28-23-1-197.dim.wideopenwest.com [23.28.197.1] 
  4    10 ms     9 ms     9 ms  dynamic-76-73-171-1.knology.net [76.73.171.1]
  5    17 ms    32 ms    19 ms  76-73-170-92.knology.net [76.73.170.92]
  6    14 ms    11 ms    10 ms  static-76-73-191-224.knology.net [76.73.191.224]
  7    11 ms    10 ms    10 ms  dynamic-75-76-35-8.knology.net [75.76.35.8]
  8    10 ms    10 ms    13 ms  as20940.xe0-0-4.chix1.ch1.unitedix.net [206.41.110.24]
  9    12 ms    25 ms    13 ms  a23-222-75-177.deploy.static.akamaitechnologies.com [23.222.75.177]

Trace complete.

C:\Windows\System32>

- It is redirected to error page - https://www.southwest.com/flight/maintenance.html

I disabled the flag - and got the same result.  So I suppose doc.write is not the problem.   Thanks for your help.  This is so frustrating. 
I am pretty sure this is related to the doc.write.   When I call it from work ( successfully)  - 
Request URL:https://www.southwest.com/flight/login?loginEntryPoint=GLOBAL_NAV_LOGIN
Request Method:POST
Status Code:302 Moved Temporarily
Remote Address:10.12.132.250:8080

and then 

type=document
Request URL:https://www.southwest.com/?int=
Request Method:GET
Status Code:200 OK
Remote Address:10.12.132.250:8080

When I do it from home - the document never loads and I am redirected to mainteneance.html. 

the remote address here is the proxy server at my work. 


There are reasons besides doc.write that could cause behavior differences between two different locations.

Happy to try to help you debug this a little further. I'll follow up via email and we can update the bug once we understand root cause.
I was experiencing this issue as well, where a script that called another script via document.write() prompted the 2G warning in the console, but seemed to silently block the script, anyway. I had multiple window.onload handlers, and reducing to only one seemed to have helped.
Well - in addition to this forum, I asked for assistance in this issue both
with my cable/ISP and with Southwest airlines (whose site I am having
issues with ).  Last night, everything worked - from multiple browsers and
different client machines.  No one has claimed any fix, but someone must
have changed something.  Thanks for your help!!
Blockedon: 698929
I can open my game now...usually can but now can't! I dont know why my connection good but i cant open the game splands.stercore.com/play-now please fix it fast!



































Status: Fixed
I'm still getting this error in Chrome.
I'm getting this error in Chrome v 57.0.2987.133 (64-bit). Is there anything I can do about as it's harming my work?
denis.scollie@gmail.com: Can you paste the dev tools logs that you are seeing. If it's just the warning without a followup error log, then this might not be the root cause.
Blockedon: 716933
Blockedon: 719203
Blockedon: 719226
Blockedon: -719226
See my error attached to this comment.
error.txt
3.5 KB View Download
My current version: 58.0.3029.110
Blockedon: 723552
Blockedon: 724843
Hi Chrome Team,

we are facing same issue with our script. where we use high bandwidth internet connection. but issue is  remain

Logs:


2jstag:2 A Parser-blocking, cross site (i.e. different eTLD+1) script, http://admarvel-d.openx.net/mw/1.0/acj?o=95414876&callback=OX_95414876&ju=f…280x894&sd=1&nl=340%2C287%2C289%2C293%2C303&ul=343%2C291%2C295%2C304%2C363, is invoked via document.write. The network request for this script MAY be blocked by the browser in this or a future page load due to poor network connectivity. If blocked in this page load, it will be confirmed in a subsequent console message.See https://www.chromestatus.com/feature/5718547946799104 for more details.
write @ jstag:2

Please help us for resolve this issue.
Thanks,
Nivrutti Pawar
Mocospace (1).html
7.9 KB View Download
When users are on fast connections (currently non-2G), this message is just a warning, and does not indicate that the script was blocked for this page load. The message says "this script MAY be blocked". The message is shown to alert developers of the page that the script can be blocked for any of your users on slow (2g) connections.

Even if you aren't concerned about users on 2G, we still recommend that you move away from using document.write to load scripts, as doing so does slow down all page loads, even for users on fast connections.
Comment 52 by 9...@915ers.com, Jul 20 (3 days ago)
this invoked even when i am on wifi in bigcommerce admin channel
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