Half of the maps do not contain heroes. EWA 2.7.1 and 2.6.2.

I installed EWA 2.7.1, then tried installing 2.6.2. In half of the maps, heroes are missing, and it's impossible to hire them in the tavern. Also, when generating a map, heroes are missing, and it's impossible to hire them. The maps are created using the map generation mode.