The ISPConfig log is /home/admispconfig/ispconfig/ispconfig.log. The system logs which command was executed in which line in which script and if the command was successful (Status: INFO) or not (Status: WARNING).
If you encounter problems with ISPConfig please have a look into the logfile and see if there are warnings. Also have a look into the logfiles under /var/log. If you cannot solve the problems on the basis of the logfiles and want to contact our support by email, please do not forget to send suspicious messages from the logs along with your email.