I downloaded Master of Orion 2 but many of the in-game features do not work. When I checked, I saw it was version was 1.40b23 which is, as far as I know, an unauthorized version. I have been playing for years and the last official version I know of was v1.31. Any versions above that were user mods of the game.

Ordinarily it wouldn't matter but I cannot build ships and am stuck with all defaults which is unacceptable.

I own the game and still have my original disk. I also have a copy of the disk and a copy of the installed game. Since it's basically a DOS game, I should have been able to simply copy my version over the top of the GoG version and it should have run.

It does ... for one game. Then, if I want to play again, I must remove the game, reinstall the game, and copy my version all over again.

Is there some way I can get the last official version to install instead of the current version you have available?

Yeah, it is patched with unofficial patch that fixes a ton of bugs.

Why is that you have problem with it? It always worked just fine for me. Never had problem with building ships and with designing my own.

Have you tried just to install patch 1.31 over it?
It can be found here.

I have both my original CD and a copy of the installed v1.31. I cannot install MoO2 on my 64-bit Windows 8.1 Pro but I am able to copy all the "installed" files on top of the GoG version. It will play just fine ... once. Then I have to delete it, reinstall the GoG version and recopy the files if I want to use my favorite version again.

With a fresh install from GoG, I am not able to design or upgrade any ships. :(

If you want to play your CD version, why not just run it in DOSBox directly instead of copying over the GOG installation?

The choice between default ships & custom ones is set up in the conditions settings at the start of each session ;)

What if you install GOG copy, copy it to different foledr and then copy your CD version over it? Does it work and does it stop working after 1 use too?

I may try to run it again but I the only options I remember seeing were:

Difficulty (I usually set it to Impossible)
Galaxy Size (I set to Huge)
Galaxy Age (I usually use Average)
Players (I set it to 8 unless I'm testing something)
Tech Level (I set to Pre-Warp)
and the three bullets I usually leave selected, Tactical Combat, Random Events, and Antarans Attack.

Once those are accepted, I choose the player race and start playing. I don't see any place where I can choose between default or custom ships. :(

[Added]
I just started a new game on my Mac and I seemed to be able to design ships on there ... at least in the early game. I wonder what the difference is between playing on the Mac and on a PC? Tried it and it doesn't work any better. Now that I've verified that it works on my Mac, I may have to go back and try on the PC again. I still want my version 1.31 though. I have managed to create a DosBox install from my disk that works kinda-sorta. Everything works except the sound. That's OK though. I usually play with the sound muted anyway as the repetition slowly drives me mad! :o

You can only design your own ships if "Tactical combat" is turned on.
Never had any problems with 1.40 version.

*ponders* wasn't it off to design? But yes, its this button which decides if design is on or off.

The only buttons I've ever turned off are Random Events or Antarans Attack. Usually not both at once though.

I am having the same problem. It's very frustrating. I am not that computer savvy and just want my game to work.

It worked when I installed it onto my last laptop. It doesn't work now after downloading it from GoG again, but onto my new laptop.

Is the exact problem that you cannot design your own ships? As already said , you need to tick that tactical combat.

You are not using a Mac, are you?

The subforum where your problem probably already has been answered: https://www.gog.com/forum/master_of_orion_series

I had issues with Drox Operative with version(s) and mods, then i dug into the actual files and found a single line to change to match the current version and then it worked. (I did look for incompatibility issues and didn't see any)

It might be similar so you might look into it.