First, set all logs in the QMC to the highest level, to gather the most information possible. Places to check within the QMC:
- System, Setup, QlikView Servers, Logging, Enable Session Logging and Enable Event Logging, set the Verbosity level to Debug (to see which requests get to the QVS)
- System, Setup, Directory Services Connectors, General, Debug Logging (to see how the QV is passing the credentials to the Custom DSC)
- System, Setup, QlikView Web Servers, General, Logging Level set to High (to see which requests get to the AccessPoint)
This may use a lot of disk space, so test it in a very controlled environment. Make sure the users are allowed to log in according to the CUSTOM Directory and that the Directory Service Connectors are set up accordingly.
Hope that helps.