So. The error I'm recieving is this.
Expression : _valid( bi.mTransform ) Function : CKinematics::CLBone File : ..\xrRender\SkeletonRigid.cpp Line : 157 Description : callback kils bone matrix bone: front_gun_tower
From what Ive been able to find on Google, this should have been fixed in the 1.3001 patch, but I'm currently playing Lost Alpha with the most recent, 1.30013 patch and yet this crash is happening whenever I complete the objective "Head deeper into the mines". I can't proceed at all without the CTD, and severely bad FPS while inside the mines. There is another post I found in the search but no one responded to it with a solution to the problem.
EDIT:
Full Error Dump
Expression : _valid( bi.mTransform )
Function : CKinematics::CLBone
File : ..\xrRender\SkeletonRigid.cpp
Line : 157
Description : callback kils bone matrix bone: front_gun_tower
XR_3DA.exe caused BREAKPOINT in module "D:\S.T.A.L.K.E.R. - Lost Alpha\bins\xrCore.dll" at 0023:6F644168, xrDebug::backend()+168 byte(s)
EAX=040C2408 EBX=808C1780 ECX=001BE487 EDX=00000001
ESI=6F66D348 EDI=80033A10 FLG=00000216
EBP=001BF3B4 ESP=001BE3A8 EIP=6F644168
CS=0023 DS=002B SS=002B ES=002B FS=0053 GS=002B