KSP 1.4.1 and Making History on Windows 10, 64 Bit: and Linux Mint 18.3 x86_64
So I started the first of the MH missions, "Dawn of the Space Age" and built the first rocket, launched it and so on. Then I quit the game, started it again and wanted to continue the mission where I left. Unfortunately, this will not work and you are placed in map view with a focus around the "sun" (shouldn't that be Kerbol?) and the date suddenly is: Year 999, Day 499 - 05:59:59. Also there is no way to access the menu in order to leave map view (e.g. select Tracking Station or Space Center).