AUTH_CUSTOM_USER_ID_HAS_BEEN_BOUND
Error Cause
CustomUserId is already associated with account, this custom user ID has been bound to another account.
Solution
- Use a different CustomUserId
- Check if the same user ID already exists
- If it's the same user, directly login with the bound account
- Unbind existing association and rebind (if you have permission)
- Contact administrator to handle account binding issue