It's level spawning section that make the system crashed. Add trigger once under condition at event 171 & 172 for quick fix.
Something like:
+ PC1: [X] Is overlapping LevelBlock
+ System: Trigger once
-> System: Create object LevelBlock on layer "Level" at (floor(PC1.X÷528)×528, floor(PC1.Y÷368)×368), create hierarchy: False, template: ""
+ PC2: [X] Is overlapping LevelBlock
+ System: Trigger once
-> System: Create object LevelBlock on layer "Level" at (floor(PC2.X÷528)×528, floor(PC2.Y÷368)×368), create hierarchy: False, template: ""
I tried this but it still didn't work... I found that it has to do with you comming close to the spawner after a few rooms. I belive that it has something to do with either the spawning or the pathfinding of the enemy.