When the cashier cannot log in, the cause may be inactive SQL Server. To troubleshoot this, please follow these steps:

• Click Start, search "Services", then click Services.

• Search SQL Server (MISACUKCUKVN)
• If the service is temporarily inactive/off, right click on it and select Start turn on.

• Log in the program again.
• After turning it on if you cannot log in, it may be due to other error. Refer to Wrong server name error here.