Have you tried reinstalling CMUD?
Did you ever right-click on CMUD and 'run as administrator'?
Did you ever run your map through the Map Conversion Tool (in ...
I've recently moved my windows installation from 7 to 10.
Since then, the cmud map file for Elephant Mud I've spent over a decade making - over 250k rooms, all coloured, named etc - now throws an 'ou ...