Creating a 'Random_Maps' folder worked great!
Just remember not to have HoMM running when you create the folder, and if the game was still running, close it and restart.

If you have a copy of the game that works, copy the random_maps folder to the game directory that is not working.


Found this works just moments ago after the same issues for a long time


Hope this helps

Okay i have read all of these posts done everything that they have said and i still can only play campaign

Me too. I'm truing to run it on Mac High Sierra, I wonder if it's because I'm adding it to the directory inside Wineskin?

I'm using macOS 10.13.3 and have just now installed HoMM3 into a new blank wrapper made from Wineskin Winery (latest is version 1.7). I used "WS9Wine2.22" engine with "Wineskin-2.6.2" wrapper, what seem to be the latest from within that application. I followed the instructions on that website, especially noting on the front page the News post for High Sierra.

After installing, I immediately started the game, selected the scenarios, and went with the first one that was offered ("Arrogance", I think). It was already set to random and I didn't change anything. I started the scenario and I went through a lot of it (maybe 3 weeks?) before the game eventually crashed.

So, I think it works and I am without any reason to believe anything is wrong with my install of the game along the lines of playing scenarios. However, I didn't try to save the game because I was just testing it.

I did not add any folders or do anything to try to get it to work. It simply worked the first time from a fresh install.

EDIT:
Oh, there's a completely different set of maps. The "Random Maps" is button for selecting that. Silly me. Yes, same error: "Cannot create Random_Map.H3M in data directory". Sorry about the confusion.

Okay, I've tried again.

I've added the directory as suggested in the previous posts and it worked for me. That means I selected "New Game", then "Single Scenario", then pressed the "Random Maps" button, then "Begin". There was a dialog saying a map was being created (without the error), and then it successfully began the map. I didn't try to play it though.

I tried "Random_Maps" as the name of the directory and it worked. I then deleted that and created it as "random_maps", without the capital letters, and that worked. So either name worked even though I have the game installed on a case-sensitive APFS partition. I did not have it installed in the "/Applications" directory nor in my personal "~/Applications" directory.

The permissions for the directory were the default of 755,
t.i. drwxr-xr-x.
Apparently no need to be writable by anyone other than myself.

So it seems rather lenient for me, not any special requirements. Just got to create that directory, and for me upper/lower case didn't matter, though it did matter for someone else according to a previous post in this thread.

The random maps directory needs to be in the same directory as the game executable, which consequently also has everything else for the game. That directory name is "HoMM 3 Complete". Or more specifically within the Wineskin Wrapper (for me at time of this post):

I am still getting this error when trying to create a random map. I have tried all of the suggestions above. Any other ideas?

Me too! I tried creating the new folder exactly as described above, but still not working either!

http://trickortweak.blogspot.com/2014/03/cannot-create-randommaph3m-in-data.html

Create a directory "random_maps" in main directory.

Cheers

Just do - click random map and after error click show random maps on the bottom of the page. Go back and click begin. It should work.