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Version of Advanced Rocketry

1.12.2-2.0.0-254-universal

Have you verified this is an issue in the latest unstable build

• Y

Version of LibVulpes

1.12.2-4.22

Version of Minecraft

1.12.2

Does this occur without other mods installed

• N/A

Crash report or log or visualVM (if applicable)

https://pastebin.com/JAYb696t

Description of the problem

Get a ClassDefNotFoundException on startup - I have a lot of mods so it's kinda difficult to discern where it comes from. My guess is it might be an issue with load order?

Update: Seems like this is an issue with JAOPCA and therefore a duplicate of TheLMiffy1111/JAOPCA#193, but I am on the current version of JAOPCA and according to @TheLMiffy1111 this should work now

Yeah the problem is with JAOPCA; had the same issue and deactivating it lets the game load.

OK, it turns out the bug with JAOPCA is applicable to the release version of Advance Rocketry, the latest Beta build is compatible as NTrixner said. I didn't realize the curse client wasn't installing the latest version