From Nao: "A small update on what might be causing this: Between 0.21.0 and 0.21.1 there was changes to files in KSP_Data\Managed folder, (Assembly-CSharp.dll, Assembly-CSharp-firstpass.dll, Assembly-UnityScript.dll and Assembly-UnityScript-firstpass.dll). By just moving the files from 21.0 to 21.1 i've managed to squash the long loading times, and that also cleared [mecanim] errors from log. Loading times still are kind of long on my PC but i think thats more of a performance issue on my PC's part, so it would be nice if somebody could confirm this (remember to backup your files ) Cheers! " Just replace Assembly-CSharp.dll with the Assembly-CSharp.dll from KSP 0.21. Problem solved,thx again Nao!