Just bought the game today.
Had to start it directly due to Steam being broken.
As in the title the game gets stuck at "Loading Expansions: Breaking Ground (1/2)".
Console threw a crapton of "Bones do not match bindpose" errors.
Using KSP version 1.4.5.
Specs are as follows:
2.6 GHz AMD Athlon 64 5000B
4 GB RAM
NVIDIA GeForce 6150SE nForce 430
Windows 7 SP1 (x86)
You don't have to tell me that these specs are lackluster.
EDIT: Forgot to mention that the game is unmodded, apart from both DLCs (Making History and Breaking Ground). Since I'm using a 32-bit operating system, I am forced to use versions prior to 1.5.