I have a problem with the GetContainerAttribute returning the correct MD5. We are trying to have Filemaker generate a MD5 Hash from a container the references an externally stored file. Our initial testing showed this to be successful on various types of files. We recently ran into a problem recently with a .iso file that is 4.8 GB and Filemaker returns a MD5 that does not match the source. We run a MD5 check on the same file with WinMD5 and the correct MD5 hash is returned. I am aware if the 4GB limitation on storing files within a container but I am not aware of en externally referenced file having any size limitations. We have not seen the issue on smaller files. Any ideas on what would cause this?