crash

[18:01:03] [User Authenticator #1/INFO]: UUID of player ancientstephanie is c29e3b52-dd9c-4767-9519-657bcea0909d
[18:01:04] [Server thread/ERROR]: Encountered an unexpected exception
java.lang.ExceptionInInitializerError: null
        at io.github.nyliummc.essentials.EssentialsChatModule$onInitialize$1.get(EssentialsChatModule.java:51) ~[essentials-module-chat-0.2.5+1.16.1.jar:?]
        at io.github.nyliummc.essentials.EssentialsChatModule$onInitialize$1.get(EssentialsChatModule.java:36) ~[essentials-module-chat-0.2.5+1.16.1.jar:?]
        at io.github.nyliummc.essentials.entities.EssentialsRegistry.getModelHandler(EssentialsRegistry.java:113) ~[essentials-base-0.2.5+1.16.1.jar:?]
        at net.minecraft.class_3222.handler$zed000$setNickname(class_3222.java:2134) ~[intermediary-server.jar:?]
        at net.minecraft.class_3222.<init>(class_3222.java:186) ~[intermediary-server.jar:?]
        at net.minecraft.class_3324.method_14613(class_3324.java:458) ~[intermediary-server.jar:?]
        at net.minecraft.class_3248.method_14384(class_3248.java:111) ~[intermediary-server.jar:?]
        at net.minecraft.class_3248.method_18785(class_3248.java:63) ~[intermediary-server.jar:?]
        at net.minecraft.class_2535.method_10754(class_2535.java:229) ~[intermediary-server.jar:?]
        at net.minecraft.class_3242.method_14357(class_3242.java:170) ~[intermediary-server.jar:?]
        at net.minecraft.server.MinecraftServer.method_3813(MinecraftServer.java:884) ~[intermediary-server.jar:?]
        at net.minecraft.class_3176.method_3813(class_3176.java:306) ~[intermediary-server.jar:?]
        at net.minecraft.server.MinecraftServer.method_3748(MinecraftServer.java:813) ~[intermediary-server.jar:?]
        at net.minecraft.server.MinecraftServer.method_29741(MinecraftServer.java:672) ~[intermediary-server.jar:?]
        at net.minecraft.server.MinecraftServer.method_29739(MinecraftServer.java:256) ~[intermediary-server.jar:?]
        at java.lang.Thread.run(Thread.java:832) [?:?]
Caused by: java.lang.ClassCastException: class java.util.concurrent.CompletableFuture cannot be cast to class java.util.Map (java.util.concurrent.CompletableFuture and java.util.Map are in module java.base of loader 'bootstrap')
        at io.github.nyliummc.essentials.modelhandlers.NicknameHandler.loadAllNicknames(NicknameHandler.java:48) ~[essentials-module-chat-0.2.5+1.16.1.jar:?]
        at io.github.nyliummc.essentials.modelhandlers.NicknameHandler.<clinit>(NicknameHandler.java:44) ~[essentials-module-chat-0.2.5+1.16.1.jar:?]
        ... 16 more
[18:01:04] [Server thread/ERROR]: This crash report has been saved to: /home/minecraft/fwogcraft/./crash-reports/crash-2020-07-23_18.01.04-server.txt
[18:01:04] [Server thread/INFO]: Removing server net.minecraft.class_3176@6d7c1b00
[18:01:04] [Server thread/INFO]: Stopping server
[18:01:04] [Server thread/INFO]: Saving players
[18:01:04] [Server thread/INFO]: Saving worlds
[18:01:04] [Server thread/INFO]: Saving chunks for level 'ServerLevel[world]'/minecraft:overworld
[18:01:07] [Server thread/INFO]: ThreadedAnvilChunkStorage (world): All chunks are saved
[18:01:07] [Server thread/INFO]: Saving chunks for level 'ServerLevel[world]'/minecraft:the_nether
[18:01:07] [Server thread/INFO]: ThreadedAnvilChunkStorage (DIM-1): All chunks are saved
[18:01:07] [Server thread/INFO]: Saving chunks for level 'ServerLevel[world]'/minecraft:the_end
[18:01:07] [Server thread/INFO]: ThreadedAnvilChunkStorage (DIM1): All chunks are saved
[18:01:07] [Server thread/INFO]: Saving chunks for level 'ServerLevel[world]'/astromine:space
[18:01:07] [Server thread/INFO]: ThreadedAnvilChunkStorage (space): All chunks are saved
[18:01:07] [Server thread/INFO]: Saving chunks for level 'ServerLevel[world]'/simplevoidworld:void
[18:01:07] [Server thread/INFO]: ThreadedAnvilChunkStorage (void): All chunks are saved
[18:01:07] [Server thread/INFO]: ThreadedAnvilChunkStorage (world): All chunks are saved
[18:01:07] [Server thread/INFO]: ThreadedAnvilChunkStorage (DIM-1): All chunks are saved
[18:01:07] [Server thread/INFO]: ThreadedAnvilChunkStorage (DIM1): All chunks are saved
[18:01:07] [Server thread/INFO]: ThreadedAnvilChunkStorage (space): All chunks are saved
[18:01:07] [Server thread/INFO]: ThreadedAnvilChunkStorage (void): All chunks are saved
[18:01:08] [ReadingThread/INFO]: Websocket closed with reason 'unknown' and code NORMAL (1000) by client!