Thank you for sharing the screenshots and other information regarding this issue. Here are the correct steps in add a domain service account to System Credentials in SupportAssist: 1.  Before performing any changes in SupportAssist, add the service account to Users on the Management Server running SupportAssist. 2. Add the service account to Administrators Group. 3.  Next open the SupportAssist console and go to Settings Tab and click on the Systems Credentials. 4.  If there are no errors, the changes will be saved successfully. Note: If there was a previous attempt in adding a specific account without first including it in the Administrators Group, then that account will not be usable without some extensive changes. If an alternative account can be used for Systems Credentials, please follow the steps above to add that account. Otherwise, we recommend submitting a ticket and working through SupportAssist Technical Support to resolve the issue.
I created a specific service account for SupportAssist called dellopenmanage that I would like to use for the system credentials.  The account is a local administrator on the server as well as part of all the available OME groups. I verified I could log into the OME site with this account.  However, when I try to set these account credentials as the system credentials for SupportAssist, I get the following error.  Unable to Connect to OpenManage EssentialsSupportAssist is unable to connect to OpenManage Essentials. Please provide the credentials of a user account that belongs to one of the following groups:   I have uninstalled and repaired both OME and SupportAssist as well as restart services, etc.  I have also confirmed that other account credentials work, including my own OME access credentials. Any ideas on what is going on?  Thanks!
Issues with SupportAssist System Credentials