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Firefox 56.02 keeps iMac with Mavericks OS 10.9.5 from sleeping. Why?

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  • Last reply by cor-el

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When Firefox 56.02 is open, my iMac running Mavericks OS 10.9.5 will not automatically go into a sleep mode. When Firefox 56.02 is closed, the computer automatically sleeps when it is supposed to. Why is this happening? How do I fix the problem?

When Firefox 56.02 is open, my iMac running Mavericks OS 10.9.5 will not automatically go into a sleep mode. When Firefox 56.02 is closed, the computer automatically sleeps when it is supposed to. Why is this happening? How do I fix the problem?

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You can try to modify multi-process settings to see if this has effect.

  • set dom.ipc.processCount to 1 if it is currently set to a higher value (4)
  • disable multi-process windows in Firefox

You can disable multi-process windows in Firefox by setting these prefs to false on the about:config page.

  • browser.tabs.remote.autostart = false
  • browser.tabs.remote.autostart.2 = false

You can open the about:config page via the location/address bar. You can accept the warning and click "I accept the risk!" to continue.