Yes, I installed the .xpi file, firefox still says my extensions are unsupported/unverified.
Reinstalling seems to work, but there are certain extensions that have data I do not want to lose. For example, if I reinstall ubock origin, I will lose all of my dynamic filtering rules.
As a side note, the value for that setting got reset after I restarted firefox.
Also, I uninstalled the fix by simply removing the extension in about:addons. Is this the correct way to do it?