The mod Warptorio 2.1 (Space Age) (0.4.3) caused a non-recoverable error.
Please report this error to the mod author.
Error while running event warptorio-space-age::on_tick (ID 0)
Can't create projectile, target not specified.
stack traceback:
[C]: in function 'create_entity'
__warptorio-space-age__/platforms.lua:239: in function 'spawn'
__warptorio-space-age__/platforms.lua:162: in function 'spawn_random'
__warptorio-space-age__/platforms.lua:122: in function 'on_tick'
__warptorio-space-age__/control.lua:2066: in function <__warptorio-space-age__/control.lua:2046>
My best guess is that the serialized platform contains a rocket that, after deserialization, no longer has a target.