It said to report this on the forums. Not sure what else to say other than I had the graphics settings on High and I have a GTX1660 Super card and was last using the DungeonMaker which had issues with a change in the name of a destination map which caused a save error.
“You can't just turn on creativity like a faucet. You have to be in the right mood. What mood is that? Last-minute panic.” ― Bill Watterson