The only reason I know of and that is almost 100% likely to cause the game to freeze is an overflow of the army variable. On which month do you release the orange hero? And are you playing the latest version of the map? This issue has been improved in that version. (latest version 07.04.2016)

I can't give you the exact date of the map. I downloaded it at the beginning of May. Here is a quote from the event: "This is the second version, in which a number of errors have been fixed, several changes have been made (including at the request and suggestions of players), and a number of new features have been added."

The freeze occurs on turn 10-4-5. If you open the map, it happens on the turn of the Devastator, who is located near the Necropolis castle.