Problem: Removed the PreconfiguredUser login module from the "admin" security configuration. Now, logins to SAP Control Center fail.
Solution: Verify server-side configuration by trying to connect to SAP Mobile Server from SAP Mobile WorkSpace (requires creating SAP Mobile Server Connection Profile with proper username and password among other things). If that works but the SAP Control Center login still fails, check for error messages ins inagent.log can offer further clues on the