Version: Repair Turret 2 1.3.0

What happened: While the turrets were upgrading a large number of belts and other entities, the game crashed with this error:

Error while running event Repair_Turret_2::on_tick (ID 0)
Target must have health.
stack traceback:
[C]: in function 'create_entity'
Repair_Turret_2/script/repair_turret.lua:2580: in function 'try_upgrade_entity'
Repair_Turret_2/script/repair_turret.lua:757: in function 'check_target'
Repair_Turret_2/script/repair_turret.lua:1076: in function 'update'
Repair_Turret_2/script/repair_turret.lua:3077: in function 'check_turret_update'
Repair_Turret_2/script/repair_turret.lua:3355: in function 'handler'

I added a log line just before the create_entity call in try_upgrade_entity that prints new_entity: log("RT2 upgrade target: " .. tostring(new_entity and new_entity.name) .. " (type: " .. tostring(new_entity and new_entity.type) .. ")")
The last line before the crash was:

RT2 upgrade target: advanced-construct-beam (type: beam)

Hey, I see you are on a pretty old version, this should be fixed in newer ones (those work on 2.1 only though)

Old version? The Mods window ingame dosent detect any newer version of Repair Turrets 2. Or do you mean the game version?
If so I do not have Space Age and at the moment it dosent seem to have an update.

Yes, I was kinda naively expecting Wube to release 2.1 as main version much earlier, so all the improvements are now on experimental (tons of them)