When attempting to start the SELECTserver service you may receive following Error 1067: The process terminated unexpectedly. The SELECTserver Administrative site, you may receive error: Server Error in '/BSS' Application. Object reference not set to an instance of an object.
The Server logs and Database Setup Utility may show Errors: Cannot open database requested by the login. The Login Failed for user 'sa'. Reason: Server is in "Single User" mode. Only one administrator can connect at this time. Invalid connection string attribute".
The SQL Server service was started and is running in a "Single User" mode and is preventing any other logins. In some cases when MicroSoft updates are pushed out to the Server it can cause the SQL service(s) to Stop and Restart multiple times, which can cause it to run in a "Single User" mode.To resolve this, simply Stop the SQL service and Start it as normal. Once the SQL Service has been started normally, it will allow multiple logins and you should be able to open the Database Setup Utility without errors. Then restart the SELECTserver service and open the Administrative Website.