Game pops up, play, game crashes. No error code given.

:(

GOG version, Windows 10, PC is more than meets requirements, avast for antivirus... any idea anyone?

This happened the first time I installed it and it hasn't happened since (Windows 7, Avast). I did exactly nothing to fix this, it seemed to be a one off bug. Bethesda gonna Bethesda. Hopefully it will be for you as well.

That could be your gog ingame overlay. Game will start but crash after a few seconds, caused by the overlay. Open the game library, goto the game click the more button, settings and uncheck the ingame overlay

If you have an intel graphics then it would be that and you get that here http://www.nexusmods.com/fallout3/mods/17209/?