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.


  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.