When I launch KSP it launches with a black screen and cursor. It isn't frozen, as the cursor still appears and can be moved around the screen and clicked (it turns green when clicked) although no way of knowing if clicking it is doing anything.
The game appears to be loading, as it is silent initially and then after pausing some time (as if loading) the main menu music kicks in.
It is likely not a graphics card problem, as I can run other games without any issues.
Things I have tried based on reading other similar problems that have not worked. Running KSP windowed, running KSP full screen, changing KSP's resolution, turning off Windows Defender, turning off Firewall (shouldn't matter, as it is excepted from the firewall anyway), launching KSP from the exe rather than through Steam, removing all mods, uninstalling and reinstalling through Steam, deleting the Kerbal Space Program folder entirely and then uninstalling and reinstalling, validating integrity of files ( but see below), deleting the exe files and forcing Steam to redownload them, updating graphic card drivers, launching 32 bit.
One interesting thing is that if I validate the files it will say everything checks out, then I will run KSP, it will be a black screen, and when I validate files again it will say 1 file failed to validate and will be reacquired. It reacquires the file, everything validates, I run KSP again, black screen, repeat. So, every time I run it 1 file appears to become no longer valid, but not sure what file or why.
Here's the KSP Log.
KSP Log
Here's the output log (split into two parts)
Output Log Part 1
Output Log Part 2
I should add that I cannot say whether this problem was introduced by the most recent patch as it had been several version releases since I last played.
Any help would be great.
Edit: See 4x4cheesecake's answer for resolution.
