I have a few addons which I have installed that won't enable. I have tried firefox 18.0.1 and 16.0.1. The addons are: the java console, fiddlerhook 22.214.171.124 and seleniumhq 10.0 ide, java console 6.0.35 and java console 6.0.37. When I install one, it appears enabled but I can't use it so I restart firefox. Upon restart, firefox opens a tab asking me to allow the addon's installation. I check, "Allow this installation" and press "Continue" but that does not work. i can go to the extensions tab and see the addon listed as disabled. Enabling from the extensions tab does not work either.
I do not see any incompatibility messages with the above mentioned addons.
hello, this sounds like the files in your profile folder that store the information about your extensions might have become corrupted. please go to firefox > help > troubleshooting information > profile - show folder... then windows explorer should open up your profile folder. in there look for the files named extensions.ini, extensions.sqlite, extensions.sqlite-journal (and in some cases also extensions.txt, extensions.rdf). delete or rename those files and quit firefox, they will be regenerated the next time you launch firefox. at this occasion also check that the contents of the profile folder are not write-protected (by right-clicking it > properties).