It crashed when I tried to use the freeplay

The mod Tech tree plus (1.4.4) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event tech_tree_plus::on_init()
Unknown interface: freeplay
stack traceback:
[C]: in function 'call'
tech_tree_plus/control.lua:48: in function <tech_tree_plus/control.lua:44>

Thank you for reporting that.

The crash it seems to be happening, because the code (and I) assumed you (and others) would only play freeplay, so I never tested it in other scenarios, whoops.
I'll look into it and update it.

Version 1.4.5 now adresses this issue.

Great, thank you very much

Great, thank you very much

Getting this Error
Failed to load mods: tech_tree_plus/prototypes/projectiles.lua:523: attempt to index field '?' (a nil value)
stack traceback:
tech_tree_plus/prototypes/projectiles.lua:523: in main chunk
[C]: in function 'require'
tech_tree_plus/data.lua:11: in main chunk

Thanks for notifying me.

However when I try to replicate it (in Vanilla + this mod) it loads and has no issues.
Can you please send me a list of mods that you are using please?
There might be something that modifies/deletes poison capsules from the base game.