https://i.imgur.com/vK1ISwZ.png

I don't know it this is fixable, but it hopefully.

I have Krastorio 2 spaced out and a few planet mods that adds a lot of research.

Edit: meant game - not save - it crashes on startup.

https://mods.factorio.com/mod/awesome-rqm has no such issue. (I probably wouldn't use both at the same time)

Sorry, I missed this when it was posted. I'll take a look over the next couple of days.

For what it is worth, I commented out line 35 in prototypes/signal.lua:
--icon_size = tech.icon_size or tech.icons[1].icon_size
It loaded, but I got another error when I tried to use it =(

I released a fix that should resolve the issue with Krastorio 2 Spaced Out (@Terrulin's issue with the icons). But I wasn't able to reproduce your issue, @ExileFox. I'm pretty sure it's one of the "planet mods that adds a lot of research". I randomly tried a few planet mods with research (Castra, Maraxis), but didn't get the issue. Can you post a mod list or if you're able to identify a specific planet mod causing the issue it would help.

here is a smaller list to trigger the issue:
https://i.imgur.com/O3bGmap.png

Failed to load mods: research-automation-combinator/prototypes/signal.lua:161: stack overflow
stack traceback:
research-automation-combinator/prototypes/signal.lua:161: in function 'tech_tier'
research-automation-combinator/prototypes/signal.lua:170: in function 'tech_tier'
research-automation-combinator/prototypes/signal.lua:170: in function 'tech_tier'
research-automation-combinator/prototypes/signal.lua:170: in function 'tech_tier'
...
... a lot of the same message
...
research-automation-combinator/prototypes/signal.lua:170: in function 'tech_tier'
research-automation-combinator/prototypes/signal.lua:170: in function 'tech_tier'
research-automation-combinator/prototypes/signal.lua:235: in function 'create_tech_signal'
research-automation-combinator/prototypes/signal.lua:287: in function 'create_initial_signals'
research-automation-combinator/data-updates.lua:3: in main chunk

Mods to be disabled:
• research-automation-combinator (1.0.1)

Edit: Seems to be Muluna that's the main problem