Restart app error--...mem could not be written...

I'm sure I can resolve the particular error with the fellow that writes and supports gSyncit. With him being a one man shop, I don't want to bother him with anything more than the solution. But I'd really like to know 'why' this sort of thing occurs. I've received a similar memory error with other software through the years and the reason has maintained a mystery.

Since the machine is closing Windows at the time I can't get a screenshot. This is my best paraphrase:

App error

W: gsyncit.exe
Instruction reference at (a bunch of 0's, I think an 'x' and...) ...memory could not be written...

In the background you can see that Windows is waiting for this program close. After clearing the memory error I then tell Windows to close gSyncit and the machine continues with the restart.

What causes this problem?

EDIT: I've read several threads on this message and it's clear there isn't one underlying cause--it can be many. I sent the email to Dave thinking he's likely familiar with what most likely is the cause.

Mark