Current questions and answers regarding the map editor.

Hello, I need help with the editor. Previously, everything was fine; I could edit maps, save them, and launch them without any issues. Then, I stopped using it for a month. A few days ago, I decided to start again. I spent several hours working on a map and happily saved it. The next day, I tried to open it, and I received this error.

Other maps that I created about 3 months ago open without any problems, but the newly created ones give me this error. I hope you can help me.