That may be why you have problems with 2.1.6 or later. I think that was the version where Tormach changed some safety features around the door and the hal-file changed as well. One way to overcome this is to copy the changes from the old files into the new files and try to start PP. When it fails, check in the log why it failed and go from there. The log is in ~/gcode/logfiles and is called pathpilot.txt (from memory).