for reasons unknown each time anyone on the modded server wins the fishing minigame it disconnects us with an internal error message

far as I can tell this is the code that displays before the crash

net.minecraft.util.ReportedException: Ticking player
at net.minecraft.entity.player.EntityPlayerMP.func_71127_g(EntityPlayerMP.java:459) ~[oq.class:?]
at net.minecraft.network.NetHandlerPlayServer.func_73660_a(NetHandlerPlayServer.java:173) ~[pa.class:?]
at net.minecraftforge.fml.common.network.handshake.NetworkDispatcher$1.func_73660_a(NetworkDispatcher.java:209) ~[NetworkDispatcher$1.class:?]
at net.minecraft.network.NetworkManager.func_74428_b(NetworkManager.java:285) ~[gw.class:?]
at net.minecraft.network.NetworkSystem.func_151269_c(NetworkSystem.java:180) [oz.class:?]
at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:790) [MinecraftServer.class:?]
at net.minecraft.server.dedicated.DedicatedServer.func_71190_q(DedicatedServer.java:397) [nz.class:?]
at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:668) [MinecraftServer.class:?]
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:526) [MinecraftServer.class:?]
at java.lang.Thread.run(Thread.java:748) [?:1.8.0_312]
Caused by: java.lang.NoSuchMethodError: levelup2.skills.SkillRegistry.getSkillLevel(Lnet/minecraft/entity/player/EntityPlayer;Ljava/lang/String;)I
at net.theawesomegem.fishingmadebetter.util.LevelUpLoot.getFishingLoot(LevelUpLoot.java:42) ~[LevelUpLoot.class:?]
at net.theawesomegem.fishingmadebetter.util.LevelUpLoot.doLevelUpLoot(LevelUpLoot.java:20) ~[LevelUpLoot.class:?]
at net.theawesomegem.fishingmadebetter.common.event.FishingEventHandler.onPlayerFish(FishingEventHandler.java:225) ~[FishingEventHandler.class:?]
at net.minecraftforge.fml.common.eventhandler.ASMEventHandler_1581_FishingEventHandler_onPlayerFish_ItemFishedEvent.invoke(.dynamic) ~[?:?]
at net.minecraftforge.fml.common.eventhandler.ASMEventHandler.invoke(ASMEventHandler.java:90) ~[ASMEventHandler.class:?]
at net.minecraftforge.fml.common.eventhandler.EventBus.post(EventBus.java:182) ~[EventBus.class:?]
at net.minecraft.entity.projectile.EntityFishHook.func_146034_e(EntityFishHook.java:522) ~[acf.class:?]
at net.theawesomegem.fishingmadebetter.common.item.fishingrod.ItemBetterFishingRod.func_77659_a(ItemBetterFishingRod.java:73) ~[ItemBetterFishingRod.class:?]
at net.theawesomegem.fishingmadebetter.common.event.FishingEventHandler.onPlayerTick(FishingEventHandler.java:380) ~[FishingEventHandler.class:?]
at net.minecraftforge.fml.common.eventhandler.ASMEventHandler_1578_FishingEventHandler_onPlayerTick_PlayerTickEvent.invoke(.dynamic) ~[?:?]
at net.minecraftforge.fml.common.eventhandler.ASMEventHandler.invoke(ASMEventHandler.java:90) ~[ASMEventHandler.class:?]
at net.minecraftforge.fml.common.eventhandler.EventBus.post(EventBus.java:182) ~[EventBus.class:?]
at net.minecraftforge.fml.common.FMLCommonHandler.onPlayerPreTick(FMLCommonHandler.java:365) ~[FMLCommonHandler.class:?]
at net.minecraft.entity.player.EntityPlayer.func_70071_h_(EntityPlayer.java:190) ~[aed.class:?]
at net.minecraft.entity.player.EntityPlayerMP.func_71127_g(EntityPlayerMP.java:382) ~[oq.class:?]
... 9 more
[22:58:57] [Server thread/INFO] [minecraft/NetHandlerPlayServer]: LoneWolfGmer lost connection: Internal server error

What version of LevelUp Reloaded is the server running? And the players?

If its any version newer than LevelUpReloaded 1.1.23 the server owner should set "levelUpPatch" in the config to false.

Will that fix the disconnecting issues?

Also I am the server owner. I just changed the setting you mentioned. And are having one of my players test if it works now.

Glad to report changing the config as mentioned above did fix my issue. Thanks for the help.