Perform ODBC Test Connection on the client PC to ensure connection the SQL Server are in-tact. Sometime SQL connection may lost due to changes in the network or windows permission, include any Windows updates.
Open ODBC from Control Panel - Administrative Tools, or search 'ODBC' from Windows Search Bar
Click Add to create a new SQL Connection
Select data source driver 'SQL Server'
Enter the SQL Server details
Select 'With SQL Server authentication' and enter SQL user credential
Select the SAP company database that you wish to connect.
Leave next screen as default and click Finish
Click 'Test Data Source..'
You shall receive a confirmation indicating the SQL Connection is successful.
Click OK to close the ODBC.