I can't reproduce it with 172.x branch on Vista with Adobe Reader 9. (the link and 
other PDF files are opened by Adobe reader plugin without any problem). 
It might be specific to Acrobat 7.0 professional. 

Please update Adobe Acrobat and try again.

I'm going to stop using Chrome because I can't get this feature to work. In a normal 
browser, there would be a way to tell the browser what to do with links. You could 
associate a MIME type with an add-on, so that it would trigger the add-on. But I 
can't find any control in Chrome that does this. I've updated Adobe Acrobat 7.0 to 
the latest settings. I set its option to open in a browser. Yet, when I click on a 
link it offers to save the file for me to the disk.

Why would the program simply stop working correctly after some period of time without 
any option to reset it to work correctly? That doesn't make sense. If this continues 
I'll be forced to go back to using Firefox. I'm not sure that's a bad outcome, but 
there are aspects of Chrome I really like, such as the way it handles tabs.

I've looked several times on the Web for anyone who's found a solution to the 
problem, but they all seem to lead back to things that don't work. For example, this 
thread says to update Acrobat and try again. If that worked, then it wouldn't be a 
problem. Another thread says that you can save the file to the disk and open it 
there. If I wanted to do that, I could right-click on the link and click "Save link 
as". I'm not looking for that. I'm looking for an answer.

I had the same problem with Vista and Acrobat Reader 8, but it was fixed when I updated 
to Acrobat Reader 9.

I have this issue with win7rc x64 en-us and Acroreader 9.x pt-br: eventually, pdf will 
open the first time, but no more pdfs will open and a blank (white) tab with a blank 
dialog box with question mark and titled Adobe Reader will open, instead - closing the 
dialog will let perceive the pdf controls briefly and the tab will close.
Closing and reopening Chromium won't help.
Currently using 3.0.183.0 (17274), but comes from previous releases.

I believe that there must be some problem with the PDF plugin in Chrome ver. 2.  I have 
been using Acrobat ver. 9 for quite some time and only encountered problems opening 
PDFs since updating.  It says that the PDF cannot be opened in Chrome with this version 
(though both versions are fully updated).  

Turns out ie8 has the exact same behaviour I described above, so it must definitely be 
a plugin problem, since reader can open the files after dl. Reader v9.1.1.

I have exactly the same problem. 

I have the same problem with Chrome. The problem just started as it worked fine before. 
Now it is back to Firefox. 

The issue (as I reported, at least) is fixed with reader 9.1.2

Unless someone has this problem with Reader 9.1.2, which you can check by navigating to 
about:plugins, I am going to close this as Invalid on July 1st.  This problem appears 
to be with the plugin and not with the browser.

Depending on the site, eg Jstor, it is still not possible to view pdfs in chrome using 
acrobat 8x (in CS3- with updates applied) on vista x64.
I wish this was fixed- it makes me revert to IE...

Ananta: it looks related to the load manually stuff?

My client has same problem, tried re-installing Chrome, upgraded from Adobe from  to 
9.0.   If he uses IE 8.0 with GoogleApps Mail it works.   Definitely a Chrome problem.

Installing the new Adobe reader fixed the problem for me.

using build 3.0.193.1 on vista 64bit
acrobat 9 professional installed

i get the same error message, that acrobat is already running, etc...

You need Reader 9.1.2.  Get the update from Adobe.

 Issue 22129  has been merged into this issue.

 Issue 13039  has been merged into this issue.

Fixed - since then Chrome has a bundled PDF plugin viewer, and Acrobat 10.1.2.45 plugin also works when that is disabled.