Was this file created using SaveToFile?

Please attach it here.

This file was truncated somehow. The header shows there were 120 items in this diagram, but the loading code reaches the end of the file while reading the 58th item (a table). All data loaded before that seems correct, so if it's something important, we can extract the first 57 items for you. Most of them seem to be links though.

It's not likely SaveToFile to return successfully if it stopped writing at the middle of an item. It should have thrown an exception of some kind, say IOException("disk full"). You might check if you are not catching and ignoring exceptions, you should report them to users instead.

If SaveToFile completed successfully, the problem could have happened because of a system crash or power outage before the HDD cache was written, or say if the file was sent as email attachment and there was a transmission error.

I hope that helps,
Stoyan