Bukkit

plugin version 2.7.2 
server paperspigot 1.16.5

i used the plugin for a while and it worked just fine. Now i can't see inventories what should i do
The message in the console:

28.03 14:22:26 [Server] WARN java.lang.IllegalAccessException: Can not set final net.minecraft.server.v1_16_R3.NonNullList field net.minecraft.server.v1_16_R3.PlayerInventory.items to net.minecraft.server.v1_16_R3.NonNullList
28.03 14:22:26 [Server] WARN at java.base/jdk.internal.reflect.UnsafeFieldAccessorImpl.throwFinalFieldIllegalAccessException(UnsafeFieldAccessorImpl.java:76)
28.03 14:22:26 [Server] WARN at java.base/jdk.internal.reflect.UnsafeFieldAccessorImpl.throwFinalFieldIllegalAccessException(UnsafeFieldAccessorImpl.java:80)
28.03 14:22:26 [Server] WARN at java.base/jdk.internal.reflect.UnsafeQualifiedObjectFieldAccessorImpl.set(UnsafeQualifiedObjectFieldAccessorImpl.java:79)
28.03 14:22:26 [Server] WARN at java.base/java.lang.reflect.Field.set(Field.java:780)
28.03 14:22:26 [Server] WARN at me.peti446.SeePlayerInventory.Inventories.PlayerInventoryEditer.reflectContents(PlayerInventoryEditer.java:38)
28.03 14:22:26 [Server] WARN at me.peti446.SeePlayerInventory.Inventories.PlayerInventoryEditer.<init>(PlayerInventoryEditer.java:29)
28.03 14:22:26 [Server] WARN at me.peti446.SeePlayerInventory.Comandos.onCommand(Comandos.java:75)
28.03 14:22:26 [Server] WARN at org.bukkit.command.PluginCommand.execute(PluginCommand.java:45)
28.03 14:22:26 [Server] WARN at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:159)
28.03 14:22:26 [Server] WARN at org.bukkit.craftbukkit.v1_16_R3.CraftServer.dispatchCommand(CraftServer.java:810)
28.03 14:22:26 [Server] WARN at net.minecraft.server.v1_16_R3.PlayerConnection.handleCommand(PlayerConnection.java:2168)
28.03 14:22:26 [Server] WARN at net.minecraft.server.v1_16_R3.PlayerConnection.c(PlayerConnection.java:1983)
28.03 14:22:26 [Server] WARN at net.minecraft.server.v1_16_R3.PlayerConnection.a(PlayerConnection.java:1936)
28.03 14:22:26 [Server] WARN at net.minecraft.server.v1_16_R3.PacketPlayInChat.a(PacketPlayInChat.java:49)
28.03 14:22:26 [Server] WARN at net.minecraft.server.v1_16_R3.PacketPlayInChat.a(PacketPlayInChat.java:7)
28.03 14:22:26 [Server] WARN at net.minecraft.server.v1_16_R3.PlayerConnectionUtils.lambda$ensureMainThread$1(PlayerConnectionUtils.java:35)
28.03 14:22:26 [Server] WARN at net.minecraft.server.v1_16_R3.TickTask.run(SourceFile:18)
28.03 14:22:26 [Server] WARN at net.minecraft.server.v1_16_R3.IAsyncTaskHandler.executeTask(IAsyncTaskHandler.java:136)
28.03 14:22:26 [Server] WARN at net.minecraft.server.v1_16_R3.IAsyncTaskHandlerReentrant.executeTask(SourceFile:23)
28.03 14:22:26 [Server] WARN at net.minecraft.server.v1_16_R3.IAsyncTaskHandler.executeNext(IAsyncTaskHandler.java:109)
28.03 14:22:26 [Server] WARN at net.minecraft.server.v1_16_R3.MinecraftServer.bb(MinecraftServer.java:1252)
28.03 14:22:26 [Server] WARN at net.minecraft.server.v1_16_R3.MinecraftServer.executeNext(MinecraftServer.java:1245)
28.03 14:22:26 [Server] WARN at net.minecraft.server.v1_16_R3.IAsyncTaskHandler.executeAll(IAsyncTaskHandler.java:95)
28.03 14:22:26 [Server] WARN at net.minecraft.server.v1_16_R3.MinecraftServer.a(MinecraftServer.java:1381)
28.03 14:22:26 [Server] WARN at net.minecraft.server.v1_16_R3.MinecraftServer.w(MinecraftServer.java:1116)
28.03 14:22:26 [Server] WARN at net.minecraft.server.v1_16_R3.MinecraftServer.lambda$a$0(MinecraftServer.java:289)
28.03 14:22:26 [Server] WARN at java.base/java.lang.Thread.run(Thread.java:834)