Glitched shadows

[FIXXER 1001]

Hi,

When ever I ride on a downloaded track my rider and bike don't cast a shadow on the track. Same with trees and other trackstuff like grandstands, not a single shadow is casted.

But, whenever I ride where there should be a shadow, the whole track gets a shadow and becomes really dark.  If I get out of the shadow the track turns back to normal. It is very annoying whenever I ride near trees with many shadows, because the track flickers dark and bright very fast.

Is there something I did wrong in the games files or am I missing a part of necessary files to use add-on tracks?

Thank you in advance.