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How do I disable the add-ons check since FF39?????

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  • 1 has this problem
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  • Last reply by cor-el

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How do I stop the add-ons compatibility check from initializing EVERY FREAKING TIME I open Firefox? This is just since the last update to version 39. I've changed the name of the .ini file in my default profile (and even deleted it) but it creates a new one every time I open the browser. I've looked in about:config but there is no longer a check.Compatability boolean entry. This is driving me nuts and I refuse to use IE. Please help before I break something!

How do I stop the add-ons compatibility check from initializing EVERY FREAKING TIME I open Firefox? This is just since the last update to version 39. I've changed the name of the .ini file in my default profile (and even deleted it) but it creates a new one every time I open the browser. I've looked in about:config but there is no longer a check.Compatability boolean entry. This is driving me nuts and I refuse to use IE. Please help before I break something!

Modified by Chris Ilias

Chosen solution

Are you using this profile with different Firefox versions?


You can check for problems with preferences.

Delete possible user.js and numbered prefs-##.js files and rename (or delete) the prefs.js file to reset all prefs to the default value including prefs set via user.js and prefs that are no longer supported in the current Firefox release.


It is possible that there is a problem with the file(s) that store the extensions registry.

Delete the extensions.* files (e.g. extensions.json, extensions.sqlite, extensions.ini) and compatibility.ini in the Firefox profile folder to reset the extensions registry.

New files will be created when required.

See "Corrupt extension files":

If you see disabled or not compatible extensions in "Firefox/Tools > Add-ons > Extensions" then click the Tools button at the left end of the Search bar to check if there is a compatibility update available.


There is software like Advanced SystemCare with its Surfing Protection feature that can protect files in the Firefox profile folder against changes. If you have such software then check the settings or uninstall this software.

Boot the computer in Windows Safe Mode with network support (press F8 on the boot screen) as a test.

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Chosen Solution

Are you using this profile with different Firefox versions?


You can check for problems with preferences.

Delete possible user.js and numbered prefs-##.js files and rename (or delete) the prefs.js file to reset all prefs to the default value including prefs set via user.js and prefs that are no longer supported in the current Firefox release.


It is possible that there is a problem with the file(s) that store the extensions registry.

Delete the extensions.* files (e.g. extensions.json, extensions.sqlite, extensions.ini) and compatibility.ini in the Firefox profile folder to reset the extensions registry.

New files will be created when required.

See "Corrupt extension files":

If you see disabled or not compatible extensions in "Firefox/Tools > Add-ons > Extensions" then click the Tools button at the left end of the Search bar to check if there is a compatibility update available.


There is software like Advanced SystemCare with its Surfing Protection feature that can protect files in the Firefox profile folder against changes. If you have such software then check the settings or uninstall this software.

Boot the computer in Windows Safe Mode with network support (press F8 on the boot screen) as a test.

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Thanks cor-el! Renamed the two .js files, the extension and compatibility files with *BAK and re-boot. Problem solved. Changing compatability.ini alone is not enough to fix this without doing the same to extension.ini and the js files (for those others of you who may share the same frustration.)

Woohoo! Cheers from Nova Scotia!

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You're welcome.

Thanks for reporting your findings and how you fixed it.