Problem/Bug HACKER in my survival

I was playing at my mc server and a random entered without having op and kicked me, he also banned me and now when i start the .bat my cmd says that:

[17:29:49] [ServerMain/INFO]: Environment: authHost='https://authserver.mojang.com', accountsHost='https://api.mojang.com', sessionHost='https://sessionserver.mojang.com', servicesHost='https://api.minecraftservices.com', name='PROD'
[17:29:50] [ServerMain/INFO]: Loaded 7 recipes
[17:29:50] [ServerMain/INFO]: Loaded 1271 advancements
[17:29:51] [Server thread/INFO]: Starting minecraft server version 1.20.1
[17:29:51] [Server thread/INFO]: Loading properties
[17:29:51] [Server thread/INFO]: Default game type: SURVIVAL
[17:29:51] [Server thread/INFO]: Generating keypair
[17:29:51] [Server thread/INFO]: Starting Minecraft server on xxx.xxx.xxxxx
[17:29:51] [Server thread/INFO]: Using default channel type
[17:29:51] [Server thread/WARN]: **** SERVER IS RUNNING IN OFFLINE/INSECURE MODE!
[17:29:51] [Server thread/WARN]: The server will make no attempt to authenticate usernames. Beware.
[17:29:51] [Server thread/WARN]: While this makes the game possible to play without internet access, it also opens up the ability for hackers to connect with any username they choose.
[17:29:51] [Server thread/WARN]: To change this, set "online-mode" to "true" in the server.properties file.
[17:29:51] [Server thread/ERROR]: Encountered an unexpected exception
com.google.gson.JsonSyntaxException: java.io.EOFException: End of input at line 18 column 1 path $[2]
at com.google.gson.Gson.fromJson(Gson.java:1224) ~[gson-2.10.jar:?]
at com.google.gson.Gson.fromJson(Gson.java:1124) ~[gson-2.10.jar:?]
at com.google.gson.Gson.fromJson(Gson.java:1062) ~[gson-2.10.jar:?]
at alp.f(SourceFile:118) ~[server-1.20.1.jar:?]
at ahd.z(SourceFile:85) ~[server-1.20.1.jar:?]
at ahd.<init>(SourceFile:24) ~[server-1.20.1.jar:?]
at ahe.e(SourceFile:161) ~[server-1.20.1.jar:?]
at net.minecraft.server.MinecraftServer.w(SourceFile:646) ~[server-1.20.1.jar:?]
at net.minecraft.server.MinecraftServer.a(SourceFile:265) ~[server-1.20.1.jar:?]
at java.lang.Thread.run(Thread.java:833) ~[?:?]
Caused by: java.io.EOFException: End of input at line 18 column 1 path $[2]
at com.google.gson.stream.JsonReader.nextNonWhitespace(JsonReader.java:1455) ~[gson-2.10.jar:?]
at com.google.gson.stream.JsonReader.doPeek(JsonReader.java:558) ~[gson-2.10.jar:?]
at com.google.gson.stream.JsonReader.hasNext(JsonReader.java:422) ~[gson-2.10.jar:?]
at com.google.gson.internal.bind.TypeAdapters$28.read(TypeAdapters.java:779) ~[gson-2.10.jar:?]
at com.google.gson.internal.bind.TypeAdapters$28.read(TypeAdapters.java:725) ~[gson-2.10.jar:?]
at com.google.gson.internal.bind.TypeAdapters$34$1.read(TypeAdapters.java:1007) ~[gson-2.10.jar:?]
at com.google.gson.Gson.fromJson(Gson.java:1214) ~[gson-2.10.jar:?]
... 9 more
[17:29:51] [Server thread/ERROR]: This crash report has been saved to: C:\Users\xxxx\xxxxxx\xxxx\.\crash-reports\crash-2023-07-31_17.29.51-server.txt
[17:29:51] [Server thread/INFO]: Stopping server
[17:29:51] [Server thread/INFO]: Saving worlds
[17:29:51] [Server thread/ERROR]: Exception stopping the server
java.lang.NullPointerException: Cannot invoke "aif.w_()" because "$$5" is null
at net.minecraft.server.MinecraftServer.a(SourceFile:541) ~[server-1.20.1.jar:?]
at net.minecraft.server.MinecraftServer.t(SourceFile:602) ~[server-1.20.1.jar:?]
at ahe.t(SourceFile:537) ~[server-1.20.1.jar:?]
at net.minecraft.server.MinecraftServer.w(SourceFile:703) ~[server-1.20.1.jar:?]
at net.minecraft.server.MinecraftServer.a(SourceFile:265) ~[server-1.20.1.jar:?]
at java.lang.Thread.run(Thread.java:833) ~[?:?]

Can anyone explain me what did this hacker do to be my server like this?