So I installed the latest version of Quark so I can add it to this custom modpack for a server I'm making and I've been hit with the error when trying to join a world due to "Invalid Player Data". Upon reading the log it seemingly indicates that the mods Lightmans Currency and Generations Core (Cobblemon Addon) are having some compatibility issues with Quark, likely a few other mods as well. Not sure if this is something fixable on Quarks end or if it'd be worth trying to fix. But thought I'd report it anyways as its a few incompatible mods. If there is a work around other than disabling/removing mods it'd be nice for someone to let me know.

latest.log

cobblemon/generations is randomly passing null to something marked as not null, report to them