[13:13:31 WARN] [Server thread]: [ServerConnectionListener] Failed to handle packet for /127.0.0.1:54842
net.minecraft.class_148: Ticking player
at net.minecraft.server.level.ServerPlayer.doTick(ServerPlayer.java:574) ~[?:?]
at net.minecraft.server.network.ServerGamePacketListenerImpl.tick(ServerGamePacketListenerImpl.java:269) ~[?:?]
at net.minecraft.network.Connection.tick(Connection.java:259) ~[?:?]
at net.minecraft.server.network.ServerConnectionListener.tick(ServerConnectionListener.java:172) ~[?:?]
at net.minecraft.server.MinecraftServer.tickChildren(MinecraftServer.java:908) ~[server-intermediary.jar:?]
at net.minecraft.server.dedicated.DedicatedServer.tickChildren(DedicatedServer.java:283) ~[?:?]
at net.minecraft.server.MinecraftServer.tickServer(MinecraftServer.java:824) ~[server-intermediary.jar:?]
at net.minecraft.server.MinecraftServer.runServer(MinecraftServer.java:671) ~[server-intermediary.jar:?]
at net.minecraft.server.MinecraftServer.lambda$spin$2(MinecraftServer.java:265) ~[server-intermediary.jar:?]
at java.lang.Thread.run(Thread.java:1583) ~[?:?]
Caused by: java.lang.NullPointerException: Cannot invoke "net.minecraft.class_1799.method_31574(net.minecraft.class_1792)" because "stack" is null
at net.minecraft.world.entity.player.Inventory.handler$dpc000$minecells$onInsertStack(Inventory.java:2191) ~[?:?]
at net.minecraft.world.entity.player.Inventory.add(Inventory.java) ~[?:?]
at net.minecraft.world.entity.projectile.AbstractArrow.tryPickup(AbstractArrow.java:553) ~[?:?]
at net.minecraft.world.entity.projectile.AbstractArrow.playerTouch(AbstractArrow.java:543) ~[?:?]
at net.minecraft.world.entity.player.Player.touch(Player.java:627) ~[?:?]
at net.minecraft.world.entity.player.Player.aiStep(Player.java:600) ~[?:?]
at net.minecraft.world.entity.LivingEntity.tick(LivingEntity.java:2419) ~[?:?]
at net.minecraft.world.entity.player.Player.tick(Player.java:283) ~[?:?]
at net.minecraft.server.level.ServerPlayer.doTick(ServerPlayer.java:510) ~[?:?]
... 9 more

initialy the client had a newer version of minecells, after this kick the server got updated. still same error when joining however. tried reverting back to .1 , worked for a while, then same thing happend.