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Flash Player playback issues in FF 19

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I have been using Chrome for a while, but I miss my Lazarus form recovery so now I'm back on the Fox

However there's a bizarre problem that has cropped up after I've re-installed the MacOS

FF 19.0.2 has significant issues with flash player, video framerate is < .5 FPS, the frame will change every time I click the mouse... otherwise the audio will play but the video will not play normally.

If I refresh the page, the video will play properly, but if I pause it, the video will go back to it's incredibly choppy frame rate. This happens with any flash based video, not just youtube.

I've updated my Flash too, but it's only in FF, Chrome doesn't have this problem.

Any thoughts?

I have been using Chrome for a while, but I miss my Lazarus form recovery so now I'm back on the Fox However there's a bizarre problem that has cropped up after I've re-installed the MacOS FF 19.0.2 has significant issues with flash player, video framerate is < .5 FPS, the frame will change every time I click the mouse... otherwise the audio will play but the video will not play normally. If I refresh the page, the video will play properly, but if I pause it, the video will go back to it's incredibly choppy frame rate. This happens with any flash based video, not just youtube. I've updated my Flash too, but it's only in FF, Chrome doesn't have this problem. Any thoughts?

All Replies (2)

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Many site issues can be caused by corrupt cookies or cache. In order to try to fix these problems, the first step is to clear both cookies and the cache. Note: This will temporarily log you out of all sites you're logged in to. To clear cache and cookies do the following:


  1. Go to Firefox > History > Clear recent history or (if no Firefox button is shown) go to Tools > Clear recent history.
  2. Under "Time range to clear", select "Everything".
  3. Now, click the arrow next to Details to toggle the Details list active.
  4. From the details list, check Cache and Cookies and uncheck everything else.
  5. Now click the Clear now button.

Further information can be found in the Clear your cache, history and other personal information in Firefox article.

Did this fix your problems? Please report back to us!

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Try Firefox Safe Mode to see if the problem goes away. Safe Mode is a troubleshooting mode, which disables most add-ons.

(If you're not using it, switch to the Default theme.)

  • You can open Firefox 4.0+ in Safe Mode by holding the Shift key when you open the Firefox desktop or Start menu shortcut.
  • Or open the Help menu and click on the Restart with Add-ons Disabled... menu item while Firefox is running.

Once you get the pop-up, just select "'Start in Safe Mode"

If the issue is not present in Firefox Safe Mode, your problem is probably caused by an extension, and you need to figure out which one. Please follow the Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems article for that.

To exit the Firefox Safe Mode, just close Firefox and wait a few seconds before opening Firefox for normal use again.

When you figure out what's causing your issues, please let us know. It might help other users who have the same problem.