This printer has a scan to email function, which had been working for months.

Suddenly, the scan to email would make microsoft outlook throw an error 0x80040109

I find that the error means that an attachment was changed in  between the time of being attached and the time being sent.

In this case I know that the file hasn’t been changed as it was scanned just a few seconds ago.

After a bit of searching, I find that the problem is most likely due to a microsoft outlook plugin.

So I start microsoft outlook, then go:

tools -> options -> other -> advanced options… -> addin manager

There are not many addins, and the only non-microsoft addin is an AVG addin.

I figure that AVG is up to its usual tricks, so I disable the AVG plugin.

I then shutdown outlook and try the scan to email…and this time it works perfectly.

If you get this error and you use another antivirus, it might still be worth trying to disable the outlook plugin for your antivirus… if it doesn’t help, then you can always enable it again.