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My add-ons act like they're installed, but don't show up. This didn't happen until after I installed FF4, had lots of trouble with it, and had to go back to FF3.5.5. Suddenly my add-ons don't work. How can I fix this?

  • 3 replies
  • 36 have this problem
  • 2 views
  • Last reply by TonyE

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I installed FF4 on both my laptop and PC, but I kept getting kicked offline, especially from Facebook. I then uninstalled FF4 and went back to FF3.5.5 (on the PC) and FF 3.6 on the laptop. This solved my connectivity issues, but add-ons are now acting up. No add-ons at all show up on the PC, and only Personas show on the laptop. When I try to install Forecast Fox and Colorful Tabs, I get the "install now" message and the message to restart FF, which I do. When it repaints, the add-ons are just not there. I expect it's something I'm doing wrong, but I don't know what it is. Java is updated. Any pointers? TIA!

I installed FF4 on both my laptop and PC, but I kept getting kicked offline, especially from Facebook. I then uninstalled FF4 and went back to FF3.5.5 (on the PC) and FF 3.6 on the laptop. This solved my connectivity issues, but add-ons are now acting up. No add-ons at all show up on the PC, and only Personas show on the laptop. When I try to install Forecast Fox and Colorful Tabs, I get the "install now" message and the message to restart FF, which I do. When it repaints, the add-ons are just not there. I expect it's something I'm doing wrong, but I don't know what it is. Java is updated. Any pointers? TIA!

Chosen solution

This can be caused if one of the files that stores details of installed extensions is corrupt.

  1. Open your profile folder, for details of how to find it see https://support.mozilla.com/kb/Profiles
  2. Close Firefox
  3. Delete the following files if they exist, extensions.cache, extensions.rdf, extensions.ini and extensions.sqlite
  4. Re-start Firefox, it will then rebuild the list on installed extensions
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Chosen Solution

This can be caused if one of the files that stores details of installed extensions is corrupt.

  1. Open your profile folder, for details of how to find it see https://support.mozilla.com/kb/Profiles
  2. Close Firefox
  3. Delete the following files if they exist, extensions.cache, extensions.rdf, extensions.ini and extensions.sqlite
  4. Re-start Firefox, it will then rebuild the list on installed extensions
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TonyE, you are a genius! Thank you so very much. I really appreciate your time and assistance. ^)^

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You're welcome