Hi If there is a problem with your extensions, it may suggest you firefox installion as become corrupt or hijacked or settings have been altered, best advice is to re-install firefox, this will automatically re-install extensions & add-ons if you have any available, however my best advice is to take a note or backup all your add-ons, themes & saved passwords using FEBE.
Then unistall firefox, before re-installing it, MAKE SURE you delete all leftover firefox folders including the hidden folders in APPDATA, PROGRAM DATA folders from your C: drive, you must delete all folders or it may just re-install corrupt files.
Its RARE for firefox extensions to stop working, very rare so to me its suggests a problem with windows not firefox, and your firefox may have been hijacked, if it as been hijacked then you are using a hijacked version of firefox that may have an hidden trojan or 2 which is blocking your extensions from working correctly. So do a trojan annd quick antivirus check.
Another possibility is that your security settings are to HIGH, (which may have been changed without your permission, this is caused by either windows, an antivirus product or antispyware product installed on your PC which is blocking all & most extensions from working, advanced antihacker software and advanced firewall programs are known for blocking add-ons and extensions from working and been executed, so you may want to check that.
I hope this advice helps, good luck and hopefully your firefox will become firefixed.
