The error log shows:
Npgsql.PostgresException: 28000: no pg_hba.conf entry for host "<IP Address>", user "qsartoolbox", database "EpiReports42".
This happens when the QSAR Toolbox Server is installed on one machine and the PostgreSQL database is deployed on a different machine. The PostgreSQL server would need to be configured to allow access to the deployed databases for the QSAR Toolbox Server Application.

 

Fix:
  1. Go to PostgreSQL server's Data folder (default folder C:\Program Files\PostgreSQL\9.6\data) and open the pg_hba.conf file.
  2. Add a line to the bottom of the file changing <ToolboxServerHost> to the IP address or hostname of the computer than is hosting the QSAR Toolbox Server.
  3. host       all           qsartoolbox       <ToolboxServerHost>   md5
  4. Restart the PostgreSQL service.
  5. Restart the QSAR Toolbox Server application/service.