[0.11.8] First steps third mission crash

[Rianaru]

as soon as the message saying I need to get iron and copper plates to build radar pops up so does this message, and then the game crashes

__level__/control.lua:209: LuaEntity API call when entity target is zero.

[kovarex]

Did you destroy one of the boilers?

Anyway, I fixed the possible way of this error, by making the boilers undestructible until this message, so it is fixed for 0.11.9

[Rianaru]

One of the boilers was destroyed by biters and then replaced, yes

[Rianaru]

and thank you for fixing this so quickly