Start Firefox in Diagnose Firefox issues using Troubleshoot Mode to check if one of the extensions or if hardware acceleration is causing the problem (switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance/Themes).

• Don't make any changes on the Safe mode start window.
• https://support.mozilla.org/kb/Safe+Mode

• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

You can also try to disable protected mode in the Flash player.

See:

• [/questions/929081]
• [/questions/928820#answer-340046]

Looking at some of the other post, I think I have the issue of having firefox 13 and flash player 11. Is there any work around to make these work togather untill they come out with an update?

If you doesn't use flash, you can simply disable it.

Firefox 13.0.1 will be released later today to fix some issues (regressions) and should include a fix for some problems with Flash 11.3. So keep an eye on this and try to update later today.

The 13.0.1 version should appear here when officially being released.

• Firefox 13.0.x: http://www.mozilla.org/en-US/firefox/all.html

I have 13.01 and it still fails. Here is the fix. Uninstall Adobe flash 11.3 and install 11.2.

https://support.mozilla.org/en-US/kb/flash-113-crashes?s=flash+assertion+fail&r=0&e=es&as=s

I do not think that downgrading flash can be concidered anything but a short term fix. If it helps right clicking on this link and going open in new tab produces the same error

Hi chainmaster1066, yes, it's a temporary workaround if other workarounds don't solve the problem (e.g., Flash 11.3 doesn't load video in Firefox). Mozilla and Adobe have been working on this, but I'm not sure when there will be a permanent solution. If you have particular symptoms you want addressed, please start a new question:

https://support.mozilla.org/en-US/questions/new