Here are two different ways to avoid the crash.
Change event 1 from "Always" to "Start of layout".
On event 2 change the order of actions so that destroy is after spawn.
Disable/Remove event 3.
Add "Sprite6" to the family "Red".
Change event 4 to the following:
+ System: For each Sprite6
+ Sprite6: [negated] Sprite6: overlaps Red : offset (0,-2)
+ Sprite6: [negated] Sprite6: overlaps Sprite2 : offset (0,-2)
-> Sprite6: Destroy