Sound like something is wrong with your Firefox installation!?
Reinstalling Addons everytime I start my browser definitely isn't the way to go.
Have you tried my solution a few posts above and/or reinstalling FF 42?
Btw. if you want to get rid of the Update Notifications
open
about:config and search for
app.update.auto
app.update.enabled
app.update.silent
and set all to "
false".
Then open explorer and enter "%LOCALAPPDATA%\Mozilla\updates" and clear that folder.
Best
J4ZZ