Thanks for sending over the files - we took a look.
First the cause appears to be that multichaind was terminated with no warning, perhaps by a Windows reboot, and this happened to interrupt a disk write operation that left the files in an inconsistent state. We've thoroughly tested that this does not happen with a hard termination on Linux, but it's possible that under Windows the underlying file system's characteristics are different and less hardy. Does this cause make sense?
Second we checked the logs and it appears you didn't yet try reindexing. Did you run multichaind with the -reindex=1 command line parameter and wait for it to finish? We can't see any sign of that in the logs.