We have a custom DB with import mode switched on and using Classic UL. On user sign-up, some users get the error “We’re sorry, something went wrong when attempting to sign up”.
If the import mode is switched on when a user signs up, the get_user script will be triggered. If a profile is returned, the generic “We’re sorry, something went wrong when attempting to sign up” error is displayed and a user account is not created in Auth0. This is because users are meant to migrate on login and not on sign-up. The user should log in to migrate the user account to Auth0.
The messaging is generic to mitigate user enumeration attacks by camouflaging the specific error. You can switch off this feature under Tenant Settings > Advanced
With the above switched off, the new error for this scenario will be
If the user signing up does not exist in the legacy DB i.e. the get_user script returns null, then a new user will be created on sign-up, but there’s no migration here anyway.