Hi @toms130 , one potential issue that trips people initially is having multiple connections enabled in the application, not just LDAP. If that is the case Auth0 may try to validate the credentials in a DB connection instead, causing this error. Can you make sure that only the LDAP connection is enabled for the application?
If it fails afterwards as well, you can check the Connector’s logs to see if the request is arriving in Connector from Auth0. This will help you confirm if the LDAP server is throwing the credentials error, or something else is going wrong.