Greetings to all!

I have a question to the esteemed community, regarding a problem I am facing now, when creating a custom scenario.

I am in the process of creating a 144x144 map, with 4 playable races, with the intent of making it a multiplayer friendly enviroment. All has been fine, until I populated and landmarked about 10% of the map. Now, after loading the scenario ingame, it crashes. Not immediately, but only after I wish to make a move with a hero. No matter where I click, it results in a crash. Otherwise the game is running fine, meaning that I can build structures in the main castle, cast spells and even summon a unit, move around with it and attack/battle other units.

For further detail , I have the latest version of GoG Disciples 2 Gold, and am making a scenario in the Rise of the Elves

The question is, of course, what might be the cause of this problem, can it be fixed, and if yes, how?

Thank you in advance for any suggestions.