The server was running normally,but suddenly an error occurred and crashed my server,and then the server automatically restart.Is there any way to fix this problem so that my server doesn't crash and restart.The server console only had a single error message,as follow:

 [Server thread/ERROR]: Encountered an unexpected exception
net.minecraft.ReportedException: Exception ticking world
        at net.minecraft.server.MinecraftServer.c(MinecraftServer.java:1478) ~[spigot-1.21-R0.1-SNAPSHOT.jar:4242-Spigot-0a642bd-515fe49]
        at net.minecraft.server.dedicated.DedicatedServer.c(DedicatedServer.java:406) ~[spigot-1.21-R0.1-SNAPSHOT.jar:4242-Spigot-0a642bd-515fe49]
        at net.minecraft.server.MinecraftServer.a(MinecraftServer.java:1321) ~[spigot-1.21-R0.1-SNAPSHOT.jar:4242-Spigot-0a642bd-515fe49]
        at net.minecraft.server.MinecraftServer.y(MinecraftServer.java:1071) ~[spigot-1.21-R0.1-SNAPSHOT.jar:4242-Spigot-0a642bd-515fe49]
        at net.minecraft.server.MinecraftServer.lambda$spin$0(MinecraftServer.java:318) ~[spigot-1.21-R0.1-SNAPSHOT.jar:4242-Spigot-0a642bd-515fe49]
        at java.base/java.lang.Thread.run(Thread.java:1583) [?:?]
Caused by: java.lang.NullPointerException: Cannot invoke "it.unimi.dsi.fastutil.ints.IntArrayList.getInt(int)" because "this.wrapped" is null
        at it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap$MapIterator.nextEntry(Int2ObjectOpenHashMap.java:663) ~[fastutil-8.5.12.jar:?]
        at it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap$ValueIterator.next(Int2ObjectOpenHashMap.java:1168) ~[fastutil-8.5.12.jar:?]
        at net.minecraft.server.level.PlayerChunkMap.l(PlayerChunkMap.java:1282) ~[spigot-1.21-R0.1-SNAPSHOT.jar:4242-Spigot-0a642bd-515fe49]
        at net.minecraft.server.level.ChunkProviderServer.a(ChunkProviderServer.java:354) ~[spigot-1.21-R0.1-SNAPSHOT.jar:4242-Spigot-0a642bd-515fe49]
        at net.minecraft.server.level.WorldServer.a(WorldServer.java:412) ~[spigot-1.21-R0.1-SNAPSHOT.jar:4242-Spigot-0a642bd-515fe49]
        at net.minecraft.server.MinecraftServer.c(MinecraftServer.java:1472) ~[spigot-1.21-R0.1-SNAPSHOT.jar:4242-Spigot-0a642bd-515fe49]
        ... 5 more