1436192 - Adobe Flash Will Not Start in Safe-Mode

Status: RESOLVED INCOMPLETE

(Core Graveyard :: Plug-ins, defect, P3)

Description

[Barry S. Finkel]

User Agent: Mozilla/5.0 (Windows NT 6.1; rv:58.0) Gecko/20100101 Firefox/58.0
Build ID: 20180128191252

Steps to reproduce:

In    https://helpx.adobe.com/flash-player.html    Flash will not run when I am in safe-mode.  I believe that this has not worked since FF 56.0, but I cannot easily revert to 55.0 to test this.

See this thread on a FF forum:

https://support.mozilla.org/en-US/questions/1176045?page=2#answer-1072526

for more details.


Actual results:

I get the message "Sorry, Flash Player is either not installed or not enabled.
Please go to step 2."


Expected results:

Flash should have either run as expected or asked me if I wanted to run Flash.

Comment 1

[Jim Mathies [:jimm]]

Chris, do you know if this is expected behavior? Doesn't sounds like it.

Comment 2

[Chris Peterson [:cpeterson]]

Barry, good catch! This is a regression in Firefox 55.

@ Felipe, this is a regression from Flash blocklist bug 1361798. If I set the `plugins.flashBlock.enabled` pref = false and restart in Safe Mode, I can load Flash correctly. Could Safe Mode prevent us from reading the Flash blocklist and then we end up in a bad state where all Flash is blocked?

I bisected this regression to the following pushlog:

https://hg.mozilla.org/integration/mozilla-inbound/pushloghtml?fromchange=1937a6c019b40fb551ca07a942ac66477605bb89&tochange=a12ce01a8b213562402c104feb1da5dcaf3030f7

There are two plugin-related changesets in that pushlog:

* Bug 1361798 to enable the Flash blocklist
* Bug 1335475 to deny plugin from non-HTTP protocols (but this change only touches test files)

Comment 3

[:Felipe Gomes (needinfo for replies!)]

(In reply to Chris Peterson [:cpeterson] from comment #2)
> @ Felipe, this is a regression from Flash blocklist bug 1361798. If I set
> the `plugins.flashBlock.enabled` pref = false and restart in Safe Mode, I
> can load Flash correctly. Could Safe Mode prevent us from reading the Flash
> blocklist and then we end up in a bad state where all Flash is blocked?

I haven't looked at the code yet, but that is probably a good assumption.

Although, is this the case of a bug that we can call a feature?

Comment 4

[Chris Peterson [:cpeterson]]

(In reply to :Felipe Gomes (needinfo me!) from comment #3)
> Although, is this the case of a bug that we can call a feature?

:) Good point. Do we even want Flash to be able to run in Firefox Safe Mode? What is the use case for that? Should we resolve this bug as WONTFIX or would we accept a fix if someone wrote a patch?

Comment 5

[:Felipe Gomes (needinfo for replies!)]

Yeah, I don't know what would be a valid use case for this.

Although probably I think we should accept a fix, because it's also tied to plugins.flashBlock.enabled, which means it has inconsistent behavior.

Comment 6

[Barry S. Finkel]

I run in safe-mode because, with my set of Firefox windows and tabs, Firefox will not run in regular mode.  This used to be true also in safe-mode, but I closed enough tabs and windows so that Firefox runs OK without usurping CPU trying to garbage-collect.  There are a few sites that I regularly visit that require Flash to run.  One is the NOAA radar image.  Another displays family trees.  A third is the Adobe web page that tells me if I have the latest Flash installed.  I do not get notified that Flash needs to be updated,so I try to check a few times each week.  I do not want Flash to run unless I authorize it.  But I definitely need Flash in safe-mode.

I once was at the Chicago Museum of Science and Industry in their Crown Space Center.  There was a NASA mission, so I was watching NASA TV.  An astronaut complained that a camera was not working.  Mission Control suggested that the astronaut power-cycle the camera.  That worked.  The astronaut asked, "Is that a bug or a feature?".  Mission Control responded, "It is a characteristic."

--Barry Finkel

Comment 7

[Chris Peterson [:cpeterson]]

(In reply to Barry S.  Finkel from comment #6)
> I run in safe-mode because, with my set of Firefox windows and tabs, Firefox
> will not run in regular mode.  This used to be true also in safe-mode, but I
> closed enough tabs and windows so that Firefox runs OK without usurping CPU
> trying to garbage-collect.

I suspect something is wrong in your Firefox user profile. You shouldn't need safe mode just to browse regular sites. Safe mode just temporarily disables your extensions and some hardware acceleration settings.

Have you tried "refreshing" your Firefox user profile? "Refreshing" will reset your Firefox settings and uninstall your extensions. But all your bookmarks, saved passwords, and browsing history will be restored. You can then re-install the extensions you need.

https://support.mozilla.org/en-US/kb/refresh-firefox-reset-add-ons-and-settings


> Mission Control responded, "It is a characteristic."

:D

Comment 8

[Barry S. Finkel]

The problem I have/had was documented in a thread on the Firefox Support Forum, and I cannot find the URL at the moment. I think it might have been bug 1308593.   The problem, as diagnosed by the support personnel, was that I had too many windows and tabs in Firefox, and, when running in 32-bit mode, Firefox was running out of memory and spending lots of time doing garbage collection.  I was running 55.0.3 for a long time until I was able to close some windows and tabs.  Then I was able to upgrade to 56.0 and 56.0.2.  But 57.0 did not work.  On January 31 I was able to close two more windows, and I then was able to upgrade to 58.0.1 and 58.0.2.  But I have not yet tried 58.0.2 in regular mode to see if it will run.  I need to try that sometime.

One thing I was never able to figure out - when Firefox was using lots of CPU doing garbage oollection, Firefox had MANY opens of file

    C:\Program Files\Adobe\Acrobat Reader DC\Reader\plug_ins\Accessibility.api

and I have no idea why.  As far as I know, I had no active tabs that were trying to download a PDF file.  This was from a two- or three-minute Process Monitor trace.  But that does not pertain to the current Flash bug.

--Barry Finkel

Comment 9

[Masatoshi Kimura [:emk]]

Could you try flipping "accessibility.force_disabled" via about:config?

Comment 10

[Chris Peterson [:cpeterson]]

You also might try install 64-bit Firefox, if you have a 64-bit Windows OS. You can download the 64-bit Firefox installer here:

https://www.mozilla.org/firefox/all/

Comment 11

[Barry S. Finkel]

(In reply to Masatoshi Kimura [:emk] from comment #9)
> Could you try flipping "accessibility.force_disabled" via about:config?

Sorry for the delay in replying.  Since I have closed some of my many tabs, I no longer have the repeated problem of Firefox spending lots of time doing garbage collection and running out of memory.  I did do a trace a few weeks ago, and I did not see the Adobe API being called.  So,flipping this setting is, for now, moot.  But I still am interested in knowing that that Adobe API does and why Firefox would be using it.

--Barry Finkel

Comment 12

[Barry S. Finkel]

(In reply to Chris Peterson [:cpeterson] from comment #10)
> You also might try install 64-bit Firefox, if you have a 64-bit Windows OS.
> You can download the 64-bit Firefox installer here:
> 
> https://www.mozilla.org/firefox/all/

There is one basic problem with your suggestion - I am running a 32-bit version of Windows 7.  I assume that 64-bit Firefox will not run in a 32-bit Operating System.

--Barry Finkel

Comment 13

[Chris Peterson [:cpeterson]]

(In reply to Barry S.  Finkel from comment #11)
> (In reply to Masatoshi Kimura [:emk] from comment #9)
> > Could you try flipping "accessibility.force_disabled" via about:config?
> 
> Sorry for the delay in replying.  Since I have closed some of my many tabs,
> I no longer have the repeated problem of Firefox spending lots of time doing
> garbage collection and running out of memory.  I did do a trace a few weeks
> ago, and I did not see the Adobe API being called.  So,flipping this setting
> is, for now, moot.  But I still am interested in knowing that that Adobe API
> does and why Firefox would be using it.

I don't know why or how Firefox would be using Adobe Reader's Accessibility.api. But this problem with Adobe Reader is unrelated to the original problem report about the Flash plugin not running in Firefox Safe Mode.

(In reply to Barry S.  Finkel from comment #12)
> There is one basic problem with your suggestion - I am running a 32-bit
> version of Windows 7.  I assume that 64-bit Firefox will not run in a 32-bit
> Operating System.

oh, you are right. 64-bit Firefox won't run on 32-bit Windows.

Comment 14

[u597032]

Flash is no longer supported.