It happened to me once. Apparently, even though the download window said that it finished downloading, I closed it before it completely finished. I downloaded again, and this time waited till download window closed by itself, and that time it was ok. It might also be because that u have a download manager and u might have paused and resumed the download, cuzing the program to be corrupted.
I was so exited to play silkroad and i also get "message string error" like wtf? can someone please help me, i don't know what to do, and i don't want to have to download it again because i know it wont help.