I am also having this problem with a newly bought KSP
Tried both the 32 and 64-bit for Steam on Windows 10. Eventually crashes when building any ship. Variable amount of time before it does though. (It doesn't immediately crash, I can get some play time in)
I "verified the integrity of game cache..." with Steam, and it said 3 files were missing and added them; though that doesn't seem to have helped any.