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Firefox Flash objects freeze up my monitor/gpu on mouseover

  • 5 replies
  • 2 have this problem
  • 49 views
  • Last reply by CSDragon

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With a few exceptions like youtube.com, any time a flash object is in a page, if I mouse over it, like to click play on an embedded youtube video, firefox becomes unresponsive, and my monitor/gpu lock up. The whole computer doesn't freeze, if I have music playing or other programs running, they aren't affected functionally, but during the monitor freeze they won't visually update. So clearly only the computer's graphics aren't updating. My monitors are connected through the GPU so it's locking up one or the other.

I have tried:

Updating/Reinstalling GPU drivers. Updating/Reinstalling Flash Updating/Reinstalling Firefox. Safe mode. Private mode Windows safe mode.

I've tried it in safe mode, so I know it's not any add-on's fault

I don't know what to do at this point other than ditch firefox, but I don't want to do that.

Windows 7. Firefox 34.0.5, but this has been happening for AGES. Flash version 16.0.0.235

GPU: EVGA GeForce GTX 660 CPU: AMD FX-8350 Black Edition

With a few exceptions like youtube.com, any time a flash object is in a page, if I mouse over it, like to click play on an embedded youtube video, firefox becomes unresponsive, and my monitor/gpu lock up. The whole computer doesn't freeze, if I have music playing or other programs running, they aren't affected functionally, but during the monitor freeze they won't visually update. So clearly only the computer's graphics aren't updating. My monitors are connected through the GPU so it's locking up one or the other. I have tried: Updating/Reinstalling GPU drivers. Updating/Reinstalling Flash Updating/Reinstalling Firefox. Safe mode. Private mode Windows safe mode. I've tried it in safe mode, so I know it's not any add-on's fault I don't know what to do at this point other than ditch firefox, but I don't want to do that. Windows 7. Firefox 34.0.5, but this has been happening for AGES. Flash version 16.0.0.235 GPU: EVGA GeForce GTX 660 CPU: AMD FX-8350 Black Edition

All Replies (5)

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Oh, and I've tried hardware acceleration on and off.

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You can try to disable OMTC and leave hardware acceleration in Firefox enabled.

  • about:config page: layers.offmainthreadcomposition.enabled = false

You can open the about:config page via the location/address bar. You can accept the warning and click "I'll be careful" to continue.


Do a malware check with several malware scanning programs on the Windows computer. Please scan with all programs because each program detects different malware. All these programs have free versions.

Make sure that you update each program to get the latest version of their databases before doing a scan.

You can also do a check for a rootkit infection with TDSSKiller.

See also:

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layers.offmainthreadcomposition.enabled = false

well that worked

that kinda baffles me though, is firefox just poorly coded for multi-thread or something?

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On a related note not described in my original issue, right clicking flash objects crashes flash (Except on the same sites where my original issue didn't apply). I thought fixing one would fix the other but apparently not.

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nvm that didn't change anything. My computer was just suddenly being agreeable for some reason.