Savegame won't load while running this mod with Spidertron Automation v2.0.34
(2.0.33 works fine)

The mod Quantum Fabrication (2.5.13) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event quantum-fabricator::on_configuration_changed
__quantum-fabricator__/scripts/process_data.lua:334: attempt to perform arithmetic on local 'product_multiplier' (a nil value)
stack traceback:
    __quantum-fabricator__/scripts/process_data.lua:334: in function 'unpack_recipe'
    __quantum-fabricator__/scripts/process_data.lua:293: in function 'process_unpacking'
    __quantum-fabricator__/scripts/process_data.lua:23: in function 'reprocess_recipes'
    __quantum-fabricator__/scripts/process_data.lua:11: in function 'process_data'
    __quantum-fabricator__/scripts/events.lua:168: in function <__quantum-fabricator__/scripts/events.lua:160>

I can't replicate it. Please upload your save somewhere, I'll take a look.

Hi, I couldn't reproduce the crash either, thought it was Spidertron Automation since that was the latest updated mod, until I noticed another mod might be at fault. I pretty much tracked down the issue to Zen Garden v0.1.6, only running that and your mod at the same time in a fresh game.

There might be other mods affected, I was able to pinpoint only this one!

Here's the save game with both mods + dependencies. Factorio Space Age 2.0.52 (experimental build)
https://gofile.io/d/3Xzwrg

Issue:
The mod adds a new technology tree (Basic Gardening), that can be unlocked by crafting 50 wooden chests. Hovering mouse over the newly unlocked items in the Quantum Fabricator GUI's landscaping tab throws a non-recoverable error.

How to reproduce:
1. Load save game, there are 49 wooden crates, craft one more to unlock the gardening tech tree
2. Open Quantum Fabricator GUI
3. Switch to landscaping tab
4. Hover mouse pointer over the tree seeds icon

The mod Quantum Fabrication (2.5.13) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event quantum-fabricator::on_gui_hover (ID 194)
__quantum-fabricator__/scripts/gui/tooltip.lua:145: attempt to concatenate local 'amount' (a nil value)
stack traceback:
    __quantum-fabricator__/scripts/gui/tooltip.lua:145: in function 'build_main_tooltip'
    __quantum-fabricator__/scripts/gui/events.lua:28: in function <__quantum-fabricator__/scripts/gui/events.lua:20>

Followup observation.
Once you research the tech, save the game, return to main menu and then reload the save, the tree seed item is gone from the fabricator GUI.
After unlocking any other tech, the tree seed item reappears in the fabricator GUI.

I see. The problem lies with my mod not supporting recipes with random amount of results. Another problem is that these recipes shouldn't even be there, because they result in trees and trees are non-blueprintable.

Both problems are fixed.