Lou,
A lot depends on which form of Antivirus you have on the computer.
Each will present a similar but different message. All of them boil
down to it saying:
We haven't seen this file very often. We don't detect any known virus
in it but not sure if you should trust it or not.
Now some systems put a clickable point on that window that leads you
to being able to say "I know where it is from, I trust it" like
Windows Defender. But others 'quarantine' it and you have to go into
that folder to get it back. Mentioning which system you use for AV
might help us get you to the right place.
-Ken Cameron, Member JMRI Dev Team
www.jmri.org
www.fingerlakeslivesteamers.org
www.cnymod.com
Ken Cameron