If I think what it is, you might have turned off car skin downloads to off. So that other's skins would appear in solid colours. To turn it back on, go to:
Was the skin that you were using at the time "XRG_DM_S14" (the one seen in the error message).
Just trying to see if that error is shown when it tries to load the skin that you have selected or when it tries to download/load someone else's skin...