Are you using the current version? The only thing I found in the forum for was for a Patch W.
What option have you selected for downloading skins? Off/512/1024?
Did you change any setting recently? Moved your data/skins or data/skins_dds folders? Reinstalled LFS?
First time I've read about this error - trying to find out how the error is prompted (maybe someone else will have better idea if you answer the above...)