I downloaded the game (yes, I ran it as administrator) but I can't use the random map generator to play games. Only the campaign games are available. Anyway to fix this? I have the h3maped.exe file.

Here you go:
https://www.gog.com/forum/heroes_of_might_and_magic_series/homm3_random_map_error/post3

hey guys,

could you please specify in which folder exactly you`ve created the 'random_map' folder?

Thanks in advance

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SOLVED

Creating folder named "random_map" in the main HOMM 3 folder (C:/ GOG Games) helps
thanks

In the folder where you installed the game.