The store page claims that this game works on Windows 10. I've tested it on two different Win 10 machines and it didn't work on both (it crashes every time I try to save my game). Any thoughts / comments? I did try the unofficial patch 1.7 and other stuff, but nope, the game simply doesn't work on Win 10. Which is fun, since Dark Reign 2 claims that it doesn't work on Win 10... while it actually does.

This should solve your problem:
https://www.gog.com/forum/dark_reign_series/update_addon_and_compatibility_fix_for_gog_and_181_windows_10

Unfortunately, no, didn't help much. That annoying CD message at start disappeared (which is a great thing), but the game still crashes every time I'm trying to save with "Strange pointer: 11A3BB80 Type=8(BUILDING)" message. I did install the game under the C:\Games\Dark Reign, I did search the entire drive C and deleted all other versions of TACTICS.CFG before starting the game, I did use your .exe files... but nope, still the same crash :(

Yeah that very bug is unfixable! The error accurs because we use 64 bit operating systems now. Dark Reign only runs well on 32 bit systems. It was never designed for it. I wish myself that somebody fixes it. And I just discovered a new bug! If you select a next song in game, sometimes 3x is enough then it freezes and there's no more music. It even crashed.

I play Dark Reign without saving.

So yeah it's a lie. But they give refunds at least.

Not being able to save is indeed a big issue for campaign play but at the very least for the original Dark Reign (i.e. Future of War) there is a (sort of) workaround by using a cheat to unlock all missions. So as tedious as not being able to save within a mission is, the campaign is playable, you just have to finish a mission in one go, which is doable.

However, for the expansion, I have not seen such an option. Is there a way to unlock all missions for it as well, e.g. by having a direct cheat or a loadable save game that can be imported? This way even in the absence of a working save system the game would at the very least become playable.

There is, I told it to someone before:
https://www.gog.com/forum/dark_reign_series/freedom_guard_mission_4_troublesome

Saving works fine on a retail copy of Dark Reign + Shadowhand.

If it's broken on GoG builds/fan patches, then it should be fixable by GoG or the people who make fan patches.

It's VERY unlikely to be a 32bit/64bit issue. I've tested a lot of old games on Windows 10 and basically none of them had issues because of that.

1.7 fan patch works too so this is probably an issue specifically with the GoG build :/

It sometimes works yeah, but after 5-10 minutes of playing it won't save it.

Played longer than that. Saved lots of times. But I did some more testing and found something interesting: the 1.7 patch crashes consistently with OP's error if the Dark Reign CD isn't inserted.

I'm guessing both fan patches and GOG builds use a no-cd crack that does something weird that's no longer supported.

OK, wow... Thanks for telling me. Didn't know that. Guess now what we really need here is some attention from GOG. Because I can't see the reason why should we have broken version here, while the original retail one works fine.

I do have the original cds too. Same problem. Linus said that it's because of 64 bit systems. I tried everything fixing it. I've got nothing! Maybe our pcs use some kind of new hardware.

Any way of alerting GOG directly to this thread to make them aware of this issue? I responded to Paczyk in the Sticky thread but if one of the games sold on GOG is not running properly, I would hope that there is a way to alert the wider staff to it.

1) It's not the only source of crashes, but from my testing it could be a major one (I just got the opportunity to test a GOG build: same thing as the fan patches).

2) Linus doesn't know anything at all about running older games on newer systems. I told you specifically to forget you watched that video because it's full of bad misinformation. Develop some critical thinking skills and don't just listen to someone because they're a celebrity.

3) I'm running Dark Reign on high-end hardware without any issues. Hardware changes hasn't really done anything significantly compatibility wise since multi-core processors were introduced and then some minor issues with 4GB RAM&VRAM. Newer GPUs can cause compatibility issues with 3D titles, but Dark Reign isn't one.

Contact Support directly.
But the saving issue is being looked at by N1 on the Dark Reign.ws discord, so we may have solution eventually.