The version above is the first paper commit where the issue appears. The commit is a re-base of upstream that, among other things, removes a mitigation for MC-142590 with the exact same symptoms as ...
at com.mna.entities.sorcery.targeting.SpellWall.m_8119_(SpellWall.java:159) ~[mna-2.0.0.27.jar%2375!/:2.0.0.27] {re:classloading} at net.minecraft.server.level ...