Which version you use? Are you using any scripts?
Viewing post in my game keeps crashing if i try to go to another level
1. Grab lastest devbuild from here:
https://cg8516.itch.io/easyfpseditor-ce/devlog/738937/bleeding-edge-builds
2. Make sure your scripts ends properly (map return/quickreturn for usual scripts and map start for map scripts respectively).