Your first priority should be to fix logging since other problems are going to be difficult to diagnose without a log.
I suspect either the log folder location doesn't exist or the permissions are incorrect. Try creating a file there with the touch command and make sure apache has write access to the file and the log folder. I typically use /var/log/iipsrv/iipsrv.log and I think there's an iipsrv configuration for the log location.