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Firefox hanging/slow—works in safe mode but deleting all add-ons didn't help

  • 7 replies
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  • Last reply by CorinaD

CorinaD
CorinaD
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Following trouble-shooting guide I isolated that browser works fine with add-ons disabled, but even with each one disabled individually, once I enabled add-ons it froze and delayed again. Finally deleted every add-on, still didn't solve the problem. There's one add-on that's disabled that I can't delete, "Adobe Acrobat - Create PDF 1.2" I don't remember adding this, but it's disabled by Firefox (which can't verify it).

Are extensions really my problem? Would this add-on be causing the problem, and how can I delete it if so? All it gives me is a "more information" link. Are there other avenues to explore?

Thanks C

Following trouble-shooting guide I isolated that browser works fine with add-ons disabled, but even with each one disabled individually, once I enabled add-ons it froze and delayed again. Finally deleted every add-on, still didn't solve the problem. There's one add-on that's disabled that I can't delete, "Adobe Acrobat - Create PDF 1.2" I don't remember adding this, but it's disabled by Firefox (which can't verify it). Are extensions really my problem? Would this add-on be causing the problem, and how can I delete it if so? All it gives me is a "more information" link. Are there other avenues to explore? Thanks C

All Replies (7)

jscher2000 - Support Volunteer
jscher2000 - Support Volunteer
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Firefox's Safe Mode actually disables a bunch of other settings besides extensions, including:

  • JavaScript compilers designed to speed up execution of complex scripts (JavaScript is interpreted the old-fashioned way)
  • Hardware acceleration of graphics and smoothing of text using your graphics card/chipset (falls back to using the CPU)
  • Custom style rules in an optional userContent.css or userChrome.css (rules ignored)

Since you described the problem as being pervasive and not limited to complex sites, perhaps it's the graphics? Could you try disabling Firefox from using hardware acceleration? Here's how:

Windows: "3-bar" menu button (or Tools menu) > Options Mac: "3-bar" menu button (or Firefox menu) > Preferences

In the left column, click Advanced. On the right side, with the "General" mini-tab active, uncheck the box for "Use hardware acceleration when available".

This takes effect the next time you exit Firefox and start it up again. Any difference?

Since hardware acceleration improves the appearance of fonts and animations, you may want to check whether graphics card/chipset driver updates are available for your system. This article suggests safe ways to do that: Upgrade your graphics drivers to use hardware acceleration and WebGL.

CorinaD
CorinaD Question owner
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Thanks! That's smart, but I've actually already disabled hardware acceleration. And yes, the problem is pervasive—spinning disc and cursors that won't appear on every page I try to open. Do you have an idea what I could check next?

Shadow110
Shadow110
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Do not advocate for any Extensions but there is one might find useful or not. Fat-Free Fox Let us know please if any changes.

cor-el
cor-el
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Note that you use a Firefox beta version (make sure to update to 55.0beta4).

Does this also happen with the regular release version?

jscher2000 - Support Volunteer
jscher2000 - Support Volunteer
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Note: I recently read a warning about downgrading from Firefox 55 to an earlier version:

Breaking profile changes - do not downgrade Firefox and use a profile that has been opened with Firefox 55+.

https://www.mozilla.org/firefox/55.0beta/releasenotes/

I haven't seen any documentation on the smoothest way to handle this. You may need to create a new profile after downgrading. Hopefully someone will clarify soon.

cor-el
cor-el
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Maybe this bug about addonStartup.json.lz4

  • Bug 1358846 - Merge extensions.ini, extensions.xpiState, extensions.bootstrappedAddons, and extensions.enabledAddons into a single JSON file
CorinaD
CorinaD Question owner
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Thanks for your help, Cor-el! I've tried downloading the stable version, and the same problem happens when I use that. You might be right about the Bug 1358846, but how do I solve it?