On the page for MoTBW I can download v2.2.1 (gog versioning) and the 1.4.5 update. However there is a 1.5.0 patch that is simply not available for download on gog. Running the game it will ask to automatically patch and download the 1.5.0 patch from the servers of the company that made the game. But those are not going to be up forever, GOG should provide that patch through their own servers as well

Actually, I think it would be better if we were able to skip installing the last update, because the game has become unplayable for me since then. After starting a shard, the game starts to freeze occasionally. After I expand and conquer more provinces in a shard, the freeze happens every other turn. I have to repeatedly alt+tab in and out of the game to click menu and exit the game, in order to save. Really annoying.

http://snowbirdgames.com/?p=1375