Issue

Error displayed during Core Installation: "login failed in user 'sa'.Reason:Server is in single user mode. Only one administrator can connect at this time."

Resolution

1. Install MS SQL Server Management Studio and open the program
2. Expand the object browser Databases and right click on the database named ulddb (this is default name)
3. Right-click the database name select Properties. Then Select the Options page.
4. Scroll down to the State section and change the Restrict Access option from single to multiple (could also be called Multi_user).
5. Once the change has been made click ok.