shmu26

Level 81
Verified
Trusted
Content Creator
Yes! Unfortunately. So I guess it is either Firefox or something related to https scanning?
Sometimes the user profile in the browser gets messed up. You could try this:
1 Make sure you are signed into your Firefox account and all your settings are properly synced.
2 Uninstall Firefox.
3 Do manual cleanup by deleting ALL Firefox folders in Appdata, and wherever else you might find them
4 Reboot
5 Reinstall Firefox, but do not sign in to your user account
6 Try to install add-ons
7 If all is well, sign in to your Firefox user account and let settings sync
8 If the problem returns after step 7, you might have to reset your user account to default settings, and rebuild it.
 

Seyyed Akram

Level 5
Sometimes the user profile in the browser gets messed up. You could try this:
1 Make sure you are signed into your Firefox account and all your settings are properly synced.
2 Uninstall Firefox.
3 Do manual cleanup by deleting ALL Firefox folders in Appdata, and wherever else you might find them
4 Reboot
5 Reinstall Firefox, but do not sign in to your user account
6 Try to install add-ons
7 If all is well, sign in to your Firefox user account and let settings sync
8 If the problem returns after step 7, you might have to reset your user account to default settings, and rebuild it.
@shmu26 Thanks for the tip but, unfortunately, uninstalling Firefox did not fix the issue (I don't have a Firefox account btw). It seems that I need to contact Kaspersky support for further help. Thank you again and thanks for @harlan4096
 

Seyyed Akram

Level 5
Uninstalling FF is not enough, You should delete manually Mozilla folder in C:\PrograData\ and in C:\Users\AppData\<your account>\Roaming\
+1
this is an important step. I haven't used Firefox in a while, but this is how I solved a somewhat similar problem with Kaspersky and Chrome, a few days ago. Simply uninstalling was not enough.
Same issue :(
I don't install extensions that much. Anyway as of now only disabling Kaspersky's protection fixes the issue.