With real Hardware same occurs some time and also like giving permission to all users in intial startup itself and all tabs the error in logger in Invalid credentails username and password.
If you have updated the project from AS4 to AS6 you need to enter the passwords for the users again due to an updated password hashing algorithm.
User Role System: Update to password hashing algorithm
Changes have been made to the password hashing algorithm. It is therefore necessary to re-enter the password for all users configured in the “Access and security/User Role System” area.
It is no longer possible to authenticate using the old stored password from the AS 4.12 project.
Has your OPCUA server started? you are focusing on some follow up errors. But before you have additional errors. Focus also on OPCUA server, did it started? you have access right set up properly?
I would personally check the configuration described here How to restore previous security behavior after migration from AS4 to AS6 . If this does not help, then analyze the complete logger and all errors and warnings there. It could be that one solved error or warning before your current one will solve it. If none of this works, get in contact with local B&R support and provide them with the project. They can check your configuration together with you, something we cannot do here at the Community.