How to enable server-side logging on Web Verification Station?
Create folder "logs" (lower case "L") in C:\inetpub\wwwroot\FlexiCapture12\Verification
Give "Full Control" access to this folder for Network Service user (or whoever runs the IIS App Pool)
After that, the logging starts automatically with log level "Error".
It is recommended to disable this after capturing the logs to avoid the build-up of files.