This issue could be caused by a port conflict. By default, the ProPunch Dashboard communicates with the ProPunch Server using port 37777.
For each file below, modify the specified setting; the port value should be changed from 37777 to another value, maybe something like 37778 or 37779 (assuming the new port value is not used by another application).
After updating each file, the computer must be restarted. After the restart, ensure the ProPunch Login page can be loaded before attempting to open the dashboard.