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Add-on efforts fail with a message that it couldn't be done because Firefof could not modigy some file; forums are no help--I am not a computer wizard and they are greek to me. HELP!

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  • Last reply by cor-el

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Sorry about the typos--Firefox and modify. The message I always get is{X} add-on "could not be installed because Firefox cannot modify the needed file". Just Google that quote and you'll get many complaints about this on your Forum, none of which is at all understandable to me. I am a longtime Firefox user, with Mac OSX 10.6.8 Macpro. Your version is 5.0.1

Please tell me how to get addons to be installed, in simple English.

Sorry about the typos--Firefo'''x''' and modi'''f'''y. The message I always get is{X} add-on "could not be installed because Firefox cannot modify the needed file". Just Google that quote and you'll get many complaints about this on your Forum, none of which is at all understandable to me. I am a longtime Firefox user, with Mac OSX 10.6.8 Macpro. Your version is 5.0.1 Please tell me how to get addons to be installed, in simple English.

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This can be a problem with the file(s) that store the extensions registry.

Delete the files extensions.* (extensions.sqlite, extensions.ini, extensions.cache, extensions.rdf) 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, not compatible, extensions in "Tools > Add-ons > Extensions" then click the Tools button at the left side of the Search Bar (or click the "Find Updates" button in older Firefox versions) to do a compatibility check or see if there is an update.