It seems about 18% of assets have null byte \0 at end of data, and the M$ XML Parser used in opensimulator barfs on it. Removing the null byte and re-saving the asset makes it good again :) purging or deleting 'corrupt' assets won't stop new ones from coming in. I fixed our asset storage and also check on new incoming assets for the null byte. I'm not sure the source, these could be legacy assets or some grid has a borked asset server or something, it's like maybe what happens if you have a C string and send an extra byte, which would be the string terminator.