I'm really enjoying this mod. Great work!

When I start processing raw uranium in a centrifuge, the game crashes with the error below.

The mod Ultracube: Age of Cube (0.3.4) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event Ultracube::on_tick (ID 0)
LuaEntity API call when LuaEntity was invalid.
stack traceback:
[C]: in function 'index'
__Ultracube/scripts/linked_entities.lua:92: in function 'tick'
Ultracube/control.lua:278: in function <Ultracube/control.lua:275>

Hey, thanks for reporting but I can't replicate this. The most likely cause is another mod not playing nice, could you upload your save file somewhere or if that's not possible provide a list of mods you're using?

(in the meantime, running /cube_refresh in the console should fix the crash for now but likely won't stop it occurring again at some point)

Thanks! Here's a link to my save file. I'm standing next to raw uranium in a chest. Feeding that into the centrifuges causes the crash right after the first ore is processed.
https://drive.google.com/file/d/163arK-5PSTvu2mkujH09agz-TH5ahU59/view?usp=sharing

Here are the currently active mods:
AAI Loaders
AAI Signal Transmission
Base mod
Better Victory Screen
Bob's Adjustable Inserters mod
Even Distribution
Factorio Standard Library
Factory Levels
Flow Control
FNEI
Honk
Inventory Sensor
Krastorio 2 Assets
Picker Dollies
RPG System
Santa's Nixie Tube Display
Simulation Helper
Text Plates
Ultracube:Age of Cube

It's an issue with Factory Levels. I will mark that mod as incompatible for now, and you can fix it by removing that mod

That did the trick, thank you!