Minecraft: 1.17.1
Forge: 37.0.34
SimplyJetpacks2: 1.17.1-2.7.1.1

There are other mods installed but it only crashes when simply jetpacks 2 is installed.
https://mclo.gs/l7k6Keu

Duplicate of #58

any chance you could give it a try with just Simply Jetpacks 2? Sadly that log contains no useful information what so ever. If there are any other logs you could find and upload, then that would be much appreciated.

Also please keep in mind that Simply Jetpacks 2 is back in beta for 1.17.1, just until any know bugs can be found and new content fully implemented. :)

new log with just simply jetpacks 2
https://mclo.gs/J97J8rQ