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Firefox 35.0 uses 100% cpu on Mac Yosemite 10.10.1 then either crashes or needs force quit.

  • 4 replies
  • 24 have this problem
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  • Last reply by jaf1948

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I have had this problem since installing Yosemite and using 34.0.5. I upgraded yesterday to 35.0 but still the same problem. Firefox will work happily for a while and then suddenly will use 100% cpu. I have disabled all extensions and plug-ins and that makes no difference. If I use Java (8-25), it will usually make it crash but not always.

To make matters worse, the crash report appears in Greek (which is being discussed in another question already).

I have had this problem since installing Yosemite and using 34.0.5. I upgraded yesterday to 35.0 but still the same problem. Firefox will work happily for a while and then suddenly will use 100% cpu. I have disabled all extensions and plug-ins and that makes no difference. If I use Java (8-25), it will usually make it crash but not always. To make matters worse, the crash report appears in Greek (which is being discussed in another question already).

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Chosen Solution

Have you tried resetting Firefox? Refresh Firefox - reset add-ons and settings

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Yes, I tried resetting and when that didn't work, I used the Mac App appcleaner to delete everything about Firefox (the program itself and all connected files but took a copy of the profile first) and did a complete reinstall. Still the same.

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Fascinating. When I was on FF 34.0.5, I did the reset as explained above and the problems were still there. I did a reset again today using 35.0, and so far the problems have not come back. I will leave it 48 hours and if there is no recurrence, I will asuume the problem is cured.

To anyone else, therefore, make sure you are on 35.0 before doing a reset (refresh).

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Problem solved !