Users suddenly are unable to access the Ares web pages and the Ares DLL logs show errors establishing a connection to the database. This problem may be caused if the SQL Server Management Studio (SSMS) application is installed at or updated to version 19 or later on the Ares server. Updating to/installing SSMS v19 or later will remove the SQL Server Native Client necessary to run Ares and cause database connection errors.
After updating or installing SSMS v19 or later, reinstall the SQL Server Native Client on the Ares server. For detailed installation instructions, see Microsoft's documentation.