Silgrad Tower from the Ashes

Hello all;
I have recently gotten the GECK for the FO series and I am having some trouble. When I load an empty cel or worldspace it's fine. But when I load anything else, it gives me this:

Assertion:

Assert
File
c:\Fallout3\Platforms\Common\Code\BSShader\BSShaderManager.cpp
Line 1996

Anyone who knows anything about this and can help me please do so.
Cheers
DD

We don't discuss the modding of other games here. :alert: A better place to direct your question would be the official forums. :check: