August 2024:
Some users have recently reported a 500 error message on the Google Auth page when attempting to log in or add their channel to TubeBuddy. To resolve this issue, please follow these steps to reset your Google Account's access to TubeBuddy.
Go to: http://myaccount.google.com/security
Scroll down to the "Your Connections to Third-party Apps & Services" section
Select TubeBuddy, then remove TubeBuddy (Delete all connections you have with TubeBuddy):
After, go back to TubeBuddy.com/sigin to sign in and accept permissions again.
If the problem persists, please get in touch with Customer Support via support@tubebuddy.com