I upgraded to V90.0.2 and tried to install Pocket. The popup gave me an old email address that does not exist, so I changed it to my current email address, logged in, but then pocket said it needed to use my email address, but the old email address was in the box and there was no way to change my old email address. I came here and logged in using my old email address, but I had updated the account so it had my new email address. I logged out and logged in with my new email address, and my settings were the same, with my new email address and my new alternate email address. No where was my old email address listed for me to change or delete. I see no way to tell FF that email no longer exists. Confusing, I know.