Workarounds and Fixes for Flash 11.3 Crashes and Problems in Firefox

It seems that the Flash 11.3 roll-out has not gone smooth for Firefox users, quite the opposite. Flash 11.3 introduces the Flash sandbox, or protected mode, to Firefox, but it seems that the security feature is causing problems in some cases. Add-ons and other plugins that enable users to record Flash videos are at least part of the problem.

Both Adobe and Mozilla are investigating the issue and there's no proper fix for all the problems just yet. Both companies have issued several workarounds for those affected by the issue. The issue only affects Windows Vista and 7 users.

Upgrade to Firefox 13.0.1

Users are reporting that videos don't play and in some cases there there are even crashes. The crashes should have been fixed with the latest Firefox 13.0.1 update, which you should definitely get, but the rest of the issues are still there.

There are several steps you can take if you are affected. If video doesn't play the problem is most likely caused by another plugin or add-on.

RealPlayer Browser Record has been blocked by Mozilla, but there's an alternative solution

Mozilla has already blocked the RealPlayer Browser Record plugin since it interfered with Flash's normal operation. The plugin will be automatically blocked in Firefox, but you can re-enable it if you want to. If you're having problems it's best to leave it disabled until Mozilla lifts the block.

Alternatively, you can disable the video downloading feature in the RealPlayer plugin. Launch RealPlayer, go to Preferences > Download & Recording and uncheck "Enable Web Download & Recording for these installed browsers" to do this.

Try disabling plugins until you find the culprit

If RealPlayer isn't the cause of your problems you will have to pinpoint the problematic plugin on your own. You'll have to disable any that you have installed one by one. First, it's a good idea to start Firefox in Safe Mode and see if problem is still there. Adobe has step-by-step instructions on how to do this.



Disable Protected Mode

If disabling plugins doesn't work, there is one last thing you can do, disable Protected Mode (the sandbox mode) in Flash 11.3. You have to edit a configuration file, mms.cfg, to do this. You'll find it at "C:\windows\system32\macromed\flash" on 32-bit Windows and "C:\windows\syswow64\macromed\flash" on 64-bit versions. Add "ProtectedMode=0" without the quotes in a new line.

Downgrade to Flash 10.3

Alternatively, though it is not recommended, you can downgrade Flash to a previous version. Mozilla points users towards Flash 11.2, but that's an unsupported version with known security vulnerabilities. The alternative is Flash 10.3 which is still supported for enterprise users.

Via: Workarounds and Fixes for Flash 11.3 Crashes and Problems in Firefox