This error showing every 1h and cause server lag, but plugin works fine, Please help me solve

[01:04:51 WARN]: java.lang.NullPointerException: Cannot invoke "org.bukkit.entity.Player.getName()" because "p" is null
[01:04:51 WARN]: at me.Newb.DeathTP.Main.save(Main.java:217)
[01:04:51 WARN]: at me.Newb.DeathTP.Main.onPlayerQuit(Main.java:197)
[01:04:51 WARN]: at com.destroystokyo.paper.event.executor.asm.generated.GeneratedEventExecutor88.execute(Unknown Source)
[01:04:51 WARN]: at org.bukkit.plugin.EventExecutor.lambda$create$1(EventExecutor.java:69)
[01:04:51 WARN]: at co.aikar.timings.TimedEventExecutor.execute(TimedEventExecutor.java:80)
[01:04:51 WARN]: at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:70)
[01:04:51 WARN]: at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:624)
[01:04:51 WARN]: at net.minecraft.server.v1_16_R3.PlayerList.disconnect(PlayerList.java:597)
[01:04:51 WARN]: at net.minecraft.server.v1_16_R3.PlayerConnection.a(PlayerConnection.java:1856)
[01:04:51 WARN]: at net.minecraft.server.v1_16_R3.NetworkManager.handleDisconnection(NetworkManager.java:520)
[01:04:51 WARN]: at net.minecraft.server.v1_16_R3.ServerConnection.c(ServerConnection.java:188)
[01:04:51 WARN]: at net.minecraft.server.v1_16_R3.MinecraftServer.b(MinecraftServer.java:1520)
[01:04:51 WARN]: at net.minecraft.server.v1_16_R3.DedicatedServer.b(DedicatedServer.java:436)
[01:04:51 WARN]: at net.minecraft.server.v1_16_R3.MinecraftServer.a(MinecraftServer.java:1347)
[01:04:51 WARN]: at net.minecraft.server.v1_16_R3.MinecraftServer.w(MinecraftServer.java:1135)
[01:04:51 WARN]: at net.minecraft.server.v1_16_R3.MinecraftServer.lambda$a$0(MinecraftServer.java:291)
[01:04:51 WARN]: at java.base/java.lang.Thread.run(Thread.java:831)

Happy to be the first review!!! I came across this plugin about a year ago. Its hard to find anything like this plugin without all the extras. This is simple and gets the job done. I rarely do make suggestions on plugins, but here I did and to my surprise the Dev was on it within the day. Overall great plugin would recommend.

Good job! But there is a warning. My discord is xKsy#7314. I can send you the warning.
But it's really a good plugin