Difference between manager & superuser - accessviolationexception

Hi I had the problem as mentionned in other threads regarding the connection problem for the DI API, with the error "Cannot connect to SBO-Common and the "accessviolationexception". It became clear to me that logging in to the UI via the command line argument to get the logged in user, and with the same user to the DI API works fine for the "manager" but not for the users u create in SBO. Is there something i forget to put in SAP so that the user gets the rights to connect to this DI API or is it a setting in SQL server, or something else ?

Could you please help me out. Have to finish this project before the end of the week

Thanks in advance