Created a separate folder as told for SPT-AKI, copy and pasted the EFT Live contents into it, installed and used the downgrader correctly, installed SPT-AKI correctly, ran server, ran launcher, logged into my account with the correct info, after a few split seconds of reaching the menu with the tree the game closes.
I managed to get a screenshot of the game version before it closed, and it is infact downgraded: 
I own a legal version of the game, seemingly installed everything correctly after reading the guide closely, I have no clue what could be messing up.
Also, the version of the game I downgraded from was 0.12.9.2.11410
I'm unsure if that has anything to do with this, so I thought I'd mention it
