Workstation can't connect to SQL database

Try switching to SQL authentication 

If that doesn't allow the user to connect, try installing the native Client Driver 11.0 on the workstation; http://www.protracker.com/Download/Tools/msodbcsql.x64.msi

Error message about Native Client 10.0 on new SQL connections

Each workstation that uses Advantage must have the SQL Native Client Driver 10.0 installed prior to connecting to the SQL Server database. Any workstations with a recent (last 3 years) installation of ProTracker should already have the latest driver.

If you have a 32-bit workstation, install this file:
https://www.protracker.com/Download/Tools/sqlncli_2008.msi

If you have a 64-bit workstation, install this file:
https://www.protracker.com/Download/Tools/sqlncli_2008_64bit.msi