failurecascade

In case it's useful to anyone, I bought the game a few days ago and found that it is playable on my relatively low-spec system: Intel i5 6600K at 3.5GHz 16GB DDR4 EVGA GTX 970 4GB VRAM I'm playing at 1080p and otherwise low settings (as close to wireframe as it will allow). Getting 50 to 60 fps in the KSC and 40 to 50 fps for launches (this dips by 10 to 15 fps when pointing the camera down to the surface of Kerbin or Mun). Note that I haven't tried assemblies of several hundred parts. Thinking that will slow the game to a crawl regardless of my hardware...

Starting with 1.8, KSP has been failing to load the DLCs whenever I started a copy of it outside of Steam. After some experimentation, it turns out that the failure is caused by a "+" character in the file system path (e.g. "c:\HDD2\KSP Instances\1.8 Stock+DLC"). Removing that "+" character from the path eliminates the problem. Other non-alphanumeric characters (e.g. "-" and "_") that I tested seemed to be fine. However, I have not tested all of them... No clue if this is a Unity 2019 problem or if it's unique to KSP, but hopefully this will help others in a similar situation.

Ok, this is a truly useful change... that I had completely missed until reading your post. Thanks @TriggerAu!