We have seen some reports of a crash on endorsement. We're not sure what causes it (since it doesn't happen for us). It is definitely an odd thing.
Two things:
1) Send support@stardock.com your debug.err file when that happens.
2) VIsit https://www.stardock.com/products/smartexception and download SmartException and install/run it. When/if that happens, send us the .cra file.
I wish I had a better answer for you. We're as stumped as you are. Endorsements, programmatically are very simple (i.e. they just increment some stats). So we're not sure why that would happen to some people.