Current questions and answers regarding the map editor.

Okay, try opening the map in the editor and clicking "check map" (on the top panel, it's a red button with a green checkmark). What does it say there?
Do you have at least two players on the map? In general, I advise you to create a new map in English, place two heroes belonging to player 1 and player 2 on it, then set the maximum level for the heroes (in map properties), and then try to launch it. If the new map appears, the problem is with the old one; if not, the problem is with the editor.