[propbeanie]

The game and the mission editor both are rather "sensitive" to any configuration differences between the ships and equipment used on them in the scenario. Some mods like FotRSU, a lot of the ship have different ClassName and Type calls. Crashing the game of course, is basically harmless, but doing a Save may well corrupt your Save folder. It would be best if you open the file in a text editor first, and check the "calls" for the ship prior to trying to run the scenarios. You could use either the Roster / Nation / Sea folder, or the Sea / ShipName folder to find both the ClassName and Type of the ship, so that you can match the scenario to the game files.