Everytime I launch ATM9 I get an error code 1 on minecraft launcher. Tried diffrent versions of ATM9.

I'm also having this issue and for me the last version which worked is version 0.2.27, if I update to anything newer I only get crashes back to launcher.

@DarthRuler Are you using RTSS which is included in MSI Afterburner by any change, because for me the crashes were caused by mod called Embeddium which is fork of Sodium mod which has bugs with RTSS so it crashes the game when it detects it.

This is the answer I got on ATM discord server:

Embeddium (Sodium) has bugs with rivatuner, which probably came with afterburner.

https://github.com/CaffeineMC/sodium-fabric/wiki/Known-Issues#rtss-incompatible