Was there a diablo.ini file already there?

Yes

Wait, i remember that there is way to enable any difficulty in any game mode. Probably first start multiplayer, than promt difficulty command promt than start single game. Im not sure if it work for already played save game... As i remeber - should work, hmm...

In multiplayer you just put command promt in chat and continue playing.

Probably chat with cheats\promts also work even in single game ad you do not needed to start multiplayer.

Actual command probably not difficlutly but players 8. Better ask google about how change diffculty in ingame for Diablo 1.

The easiest way (legal without any mods) to change the difficulty in Single Player is to load your character from Multiplayer (20 level if you want to play Nightmare and 30 level for Hell). After that --> New Game ->Cancel -> Single Player --> Load your character from Single and it's done. That's why I need a save cause I have 33 lvl single character and I don't wanna start again in Multi...

Good thing that I needed a break from the game, but I will probably play Multi myself next week if I will not find any solution (didn't expected it will be so hard but well).

So... any new ideas?

it worked for everyone else, I offered to help over teamviewer, you refused, thought you were supposed to figure it out on your own and now you are asking for "ideas"? :)

Thank you very much for sharing this. Everything seems easy and all but it doesn't work for me. I will try to give more specific questions after every step.

1. Ok I downloaded the same version from the same source.

2. I don't understand next step. Where should I put it? Why your DevilutionX file is in the Download folder, and after a second you copy him to Desktop?? Where did you install the game and GOG?

All my files (gog, the game and devilutionx is in the same folder but I tried in different folders too and still the same info).

3. DIABDAT.MPQ or diabdat.mpq? I tried both and doesn't work.

4. After this I'm clicking devolution.exe and...

"Data File Error"
Unable to open diabdat.mpq
Make sure it is in a game folder and that the filename is in all lowercase" - so it should be in the game folder or not?? I tried both.

5. I have checked antivirus - I even uninstall it - still doesn't work.

6. I will try to record a movie to prove I'm doing the same - seriously I know it's obvious but something that's not in this movie must be the reason why it doesn't work.

Once again thanks for your help and patience.

Ok but what's the point of writing about our private conversation here? I'm looking for help from other users and that's it.

It's up to you where you put it, I just put it on the desktop because that is easy to see.

The download is a zip file, Chrome saved it in Downloads, I extracted the content by draging it to the desktop. Maybe you have installed some other application for handeling zip files but what I show in the video is how it work by default in Windows 7.

I copied the MPQ to the desktop to make it easy to see what file you need. It doesn't matter where your GOG instalation is.

Did you ever check the file permissions? Probably you have set file permissions on the MPQ so that only an admin can access it.

I'm 90% sure something is wrong with your system. Could you try on a different one, or a VM like I did.

https://developer.microsoft.com/en-us/microsoft-edge/tools/vms/

Thanks for explaining this.

I'm using 7-zip for extracting the files but it probably doesn't matter.

You were right, I forgot to check the file permission. I never changed anything there but I checked the MPQ file, changed permission from Admin to user (I have a few options there and tried everything). After this - still the same.

But I just found something that might be helpful. If you can so easily change the difficulty - even for level 1 character - can you please sent me your new multiplayer save with level 1 character on Hell difficulty? I think this might help and I won't be needed level 30 multi char. If this doesn't help I will try your VM method.

" can you please sent me your new multiplayer save with level 1 character on Hell difficulty?" - that's ... not how it works ...

Did you test it? Well, I'm almost 90% sure it will work. It's not about the level but difficulty settings.

It won't work, you need to use the workaround when resuming save games in the original game so you would be stuck at the exact same point.

But workaround is only when I want to change difficulty in single player. If I had a save from multi (no matter which level) are you sure it won't work? Just test it if you can: new game -> multi > hell difficulty.

Next New game, cancel, load game single player character (can be level 1) and go to the dungeon. If you have at least 300-400 gold from the chest that means it's working - it's probably no more than 2 minutes to check.

Diablo does not have the ability to save multiplayer games. It can save multiplayer heroes, but heroes have no difficulty level associated with them. A multiplayer save is a new feature in DevilutionX, so even if someone sent you such a save, you would need to use DevilutionX to be able to open it. Based on the earlier part of the thread, you have not gotten DevilutionX to run for you, so you would not be able to use a multiplayer save.

If you could get someone to send you a multiplayer hero file, you could use that to do what you want.