I've had this problem before, but I was able to resolve it that time. macOS 10.13.4, everything up to date. Yesterday, Internet Accounts forgot my LinkedIn password and would not reauthenticate. Today, it forgot my Facebook password.
I've tried:
- App specific password.
- Removing the account and re-adding it.
- Turning off 2-factor authentication.
- Deleting associated entries from Keychain.
- Logging out of iCloud, deleting Keychain entries, removing and re-adding the account, then logging back in.
First of all, what the hell—why does this keep happening?! Secondly, what else can I do to fix this short of reinstalling macOS?