Running the Gen Client Server Encyclopedia (CSE) Configuration utility (cse_config.exe) on Windows with SQL Server gives "Error -1 while running Encyclopedia initialization".

The error occurs after "Begin applying configuration ... Initializing Coordination tables"

Looking in the cfg and log folders, but do not see any log files that would help troubleshoot the error.

The Gen CSE is a 32-bit application so the 32-bit version of the SQL Server Client (and Tools) needs to be installed and a 32-bit ODBC System Data Source Name (DSN) needs to be created as well as a 64-bit DSN.

Create both 32-bit and 64-bit ODBC System Data Source Names (DSN) for the CSE Coordination and Encyclopedia Databases or for the single Database if that combined option is being used.
This doc. page has further details:
Gen™ 8.6 > Encyclopedia > Client Server Encyclopedia > Using the Client Server Encyclopedia > Install and Configure CSE > Prerequisites for CSE - see "Create Microsoft SQL Server CSE Database"