Factorio Forums

Hello!

Yesterday while playing my modded factorio (K2Space age + other lesser ones), I was eager to finally research flamethrower turrets both for offense and defense. To my shock though, I couldn't.
It stated that I "Lacked prerequisite technologies" despite having Military tech cards reserached.
After messing with my mods to see which might have made problems, I realized I was missing an entire tech for some reason "Flamables"
Oddly enough, on the same world/seed/modlist in a new game, the tech is there. It's just missing in my current save game.

I don't think I hid or removed it somehow, not experienced if that is even possible. AFAIK no mod's doing it as it shows up on a new game perfectly fine, just my save's cursed.

Here's images to explain it. There should be a prerequisite tech named Flamables next to the Fuel one (red machine) The modlist if needed

Usually, techs "disappear" when there are modified/replaced by a mod, which is subsequently deactivated.
If you started playing with a mod that changed or removed the tech, and decided to deactivate that mod, then you get this result.

Can't guarantee it's the root cause though.

[Edit] : This might help : https://wiki.factorio.com/Console#Reset ... to_default

Would updates to mods do it as well?
Had one that needed to remove features from itself to fix a bug.
Other than thats I haven't touched the modlist at all, no removals or additions, though I wish I checked all tech at the start..

I also tried the command, and I guess it went through? Got a warning and it disabled all achievements, but still nothing. [EDIT]
I tried giving it to me using a command and that worked somewhat?
The technology still doesn't show up as researched, but techs that need it are researchable now Half convinced it's just hidden, but I'm no expert in this field
I checked the techs and it's clearly there researched. I missed it first time typing.
Also checked my earliest save and the tech was missing there as well.

Well I ended up adding the research using dev/lua commands and then removing it for me to legitimatelly research it later on.

A weird bug but thank goodness for commands.

Koub wrote: Wed Oct 01, 2025 2:24 pm Usually, techs "disappear" when there are modified/replaced by a mod, which is subsequently deactivated.
If you started playing with a mod that changed or removed the tech, and decided to deactivate that mod, then you get this result.

Can't guarantee it's the root cause though.

[Edit] : This might help : https://wiki.factorio.com/Console#Reset ... to_default

Shouldn't the tech be available in this case? When you deactivate a mod that removed a technology, it will load during the data stage as there's nothing left that removes it

Natha wrote: Wed Oct 01, 2025 7:42 pm Shouldn't the tech be available in this case? When you deactivate a mod that removed a technology, it will load during the data stage as there's nothing left that removes it

I honestly don't know. I have observed over years on this forum that, for people complaining about missing techs, the "had a mod remove/replace a tech, and stopped using the mod mid-game" was a common root cause.