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I cannot install add-ons in Firefox 42.0

  • 5 replies
  • 1 has this problem
  • 7 views
  • Last reply by cor-el

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My firefox was very slow. I did a tune-up. After that when I tried to install add-ons, nothing happens. It goes fine till the restart to use add-on, then there is nothing.

My firefox was very slow. I did a tune-up. After that when I tried to install add-ons, nothing happens. It goes fine till the restart to use add-on, then there is nothing.

All Replies (5)

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I need auto refresh for my work, and it is pretty troublesome for the last three days with this issue. Have uninstalled, removed all previous Mozilla files, configuration files, but it is still the same. It would be good if someone could shed some light onto it. Otherwise the only option is to move to Chrome permanently :(

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Can you open "about:config" and search for "xpinstall.signatures.required". Is it set to "True"?

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Hi zikzak, thanks for getting back ... "xpinstall.signatures.required" is set to false. What and how do I change it to?

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No need to change it, I wanted to make sure that your install allows unsigned addons, it is the case so that's not the reason of your issue.

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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 menu button/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.

If this hasn't helped then also delete the addons.json file.