edit: Nevermind. The crash was caused by the mod "MontyHaul Inventory and Gold Expander". It is not compatible with DS1 LOA. It only works with original DS1.

original message: I just tried this method with DS1, but when I start a new single player game in any world, the game just presents its usual "Preparing World" and "Microsoft presents..." and then the game crashes with an access violation when it tries to transition to the game world. This only happens with the "DungeonSiege.exe" from Killah's fix (version 1.50). If I replace "DungeonSiege.exe" with the original file from the GOG install (version 1.11.1) the game runs fine and doesn't crash, but then I can't play LOA.

The GOG version has a "RDNA fix" included and I'm using a RDNA based graphics card, so I guess the crash is connected with the GPU. The funny thing is that even the original CD version of DS1 runs fine on this PC.

Is there any fix for AMD GPU users to get Killah's mod running?

I already tried windowed mode and switching graphics features on and off to no avail.

Just did some research before I was going to replay the game, finally with the expansion this time and beware:

If you plan on playing the original campaign first, only install Legends of Aranna after you finish it. The expansion introduces some changes that work retroactively, but the original game was not prepared for. Most notably this:

https://www.nexusmods.com/dungeonsiege1/mods/90?tab=description

Skill levels now affect damage dealt by the respective weapons/spells by countering enemy armor. Aranna campaign was balanced for it, but the original game was not, in many places. This leads to the game being VASTLY easier in many spots because many enemies did not have their skill levels, properly set to account for the new skill vs armor scaling.

The linked mod is included in the download to enable Legends of Aranna, so everyone who did this has it. It attempts to restore the original experience to the vanilla campaign, but is most likely not a 100% match, as mentioned in the comments of the mod.

For the nitty gritty of if, there is this page, which also lists several of the formulas that have been changed with the expansion:
https://dungeonsiege.fandom.com/wiki/Character_Leveling_and_Spell_Guide#Armor_Rating

To make it short, the expansion drastically reduced the importance of armor and raw damage and put more emphasis on skill levels themselves. Not really a change I like to be honest, as it just makes DPS the most important stat on every weapon, no matter what. Originally, it was always a contest between the raw DPS of fast weapons and the penetrative power of slow weapons. Vastly higher DPS weapons could result in less actual DPS against high armor targets. Same for spells, where some send out several low damaging projectiles for more total damage, or one that deals less damage but in a single instance. Now more DPS is always the better option.

Also, having the expansion installed makes it so the expansion items can now drop in the Ehb campaign. Meaning you will be encountering Zaurask, Hassat and other expansion themed gear in an environment where it makes zero sense and can be somewhat immersion breaking. Not to mention that the base campaign was absolutely not built around the comparably much stronger gear from LoA.

So if you want a genuine vanilla campaign experience, play it first. There is no reason to have Aranna installed for the base campaign, as you have to start over in the expansion campaign anyway.

I am actually glad now that the officially sold version is just the base game. My recommendation if you want to play everything is:
1) GOG install - Main Campaign
2) Grab Yesterhaven from the internet and play though that. It was made before LoA, so should also be played in vanilla conditions.
3) Install and play through LoA
4) Play Return to Arhok

That's the chronological order and you'll play them all the way they were intended.

Continuing my ranting on the expansions, this time for DS 2:

If you install BW from the linked guide, it will absolutely annihilate your framerate. Standard DS 2 install works perfectly fine, but having BW installed (from the Killah's fix at least) will tank your framerate to the ~30s. I just restarted the game without BW after having reached act 2 with BW, because the eye strain was unbearable.

Additionally, for archival purposes, I will list all the things I could gather that BW changed compared to the original game. Both from experience and scouring the net:

1) Most skills have been noticeably nerfed in BW. Original DS has a hard skill cap of 20 points on every skill. BW raised that to 30 (skill point cap is still 20, but items can boost it to 30), but also nerfed the values per point on most skills. In many cases, even 30 points in BW is weaker than 20 points in DS 2. Some of the powers have also been nerfed.

The base game was ridiculously easy and Broken World attempted to change that, somewhat successfully. Now, even normal difficulty can offer some challenge.

2) Armor values of all armor pieces have been drastically reduced. Think 30-40% cut in most cases. This results in incoming damage being vastly higher than in the original DS 2.

3) A couple monster templates have been messed with improperly, which causes enemies from the BW campaign to spawn in the main campaign. You will likely encounter level 35 or so enemies near the start of act 2 in a side area (where you will be around level 16), meaning you will be doing basically no damage to them and they will one shot your until the levels get somewhat equalized. There is also a later spot, where you will encounter level 45 heroes while you are around level 30, which can easily wipe you if you're not prepared.

4) Then of course, you have the additional itemization changes. There is a lot more gear, especially for the 2 new classes. This can be a boon and a curse. If you utilize any of the 2 new expansion classes, you will of course be glad it exists. However, if you only play with the 4 vanilla core classes, the dilution of the drop pool by the expansion items can become somewhat annoying, where a lot of drops will be simply useless unless you have one of the expansion classes in your party.

There are also a lot of new affixes, but from what I can tell, most of them are pretty meh (like chances to proc various effects on hit and when hit.... gotta copy Diablo 2 in any way possible eh?), and a few are good. Generally, it seems much harder now to find useful rare items due to the introduction of many new affixes which dilute the pool with mostly mediocre to bad options, putting even more emphasis on sets and legendary items, which have pre-set bonuses.

5) Respec. BW adds an option to respec, which is not available in pure DS 2.

6) Reagent Recipes. Special recipes can drop with BW, through which you can create unique/set items. Makes enchanting and using reagents not as useless as in the original game.

7) BW adds 2 extra spell auto-cast slots, meaning it's now possible to have up to 4.

Hello, I've followed your recent exchange with MysterD concerning the Dungeon Siege series and its expansions. May I ask you if you tried to install the retail version of Broken World on top of GOG's version of Dungeon Siege 2? How did it go? Were you able to make it work smoothly in terms of framerate?

Hi.

Nope, as it hasn't arrived yet. Ordering from the US Amazon, the shipping can take a while. Should probably get here by the end of next week or so. Will try it both with retail and GOG version.

The main thing is however, that from retail, you get 2 separate .exes. One for the original game, one for Broken World. Which should mean, that it's probably going to be possible to play at least the base game with normal framerates, even if Broken World still has the problem. The base game both from retail and GOG runs with perfect framerates.

The Steam guide for getting Broken World merges both the base game and the expansion under a single .exe, so you can no longer launch them separately and this .exe completely tanks the FPS. As an experiment, to see how low I can get the FPS to go, I am currently playing and not quitting the game at all (only minimizing and sleeping the PC overnight before coming back to it). Currently, the game's FPS is in the ~25 territory with dips below 20 during bigger fights. My eyes hate me for it though...

OK, thank you for experimenting - I'll stay tuned, then!

Sad to report that the issue has been there since Broken World came out.

Installed both DS 2 and Broken World from the boxes and played through the tutorial using both .exes. Completely vanilla files, the only thing I did was launch the games in windowed mode as there is an issue on modern Windows where the cursor is missing in fullscreen. When windowed, the game is hard capped to 75 FPS.

Results:
Base game's .exe - absolutely stable and unflinching 75 FPS from start of the tutorial until the first town.

Broken World .exe - starts at 75 FPS but deteriorates as you play. Dips below 40 FPS are frequent by the end of the tutorial.

At least we can now safely say that the FPS issues were NOT introduced by Killah's fix. It's been there since the start.

Last thing I'll try is doing it on a Windows XP PC in a week or two.

Thanks a lot for reporting back. Sad news indeed - it seems there is no way to play Broken World smoothly, in the end. Or maybe there is - but there are different possible workarounds that work differently, depending on context, with no clear solution. I mean, you can find many suggested fixes if you do a web search, some say one worked for them, others say it didn't...
Now I'm curious to see what happens with XP.