Player Data Failed to be Saved

Hello I got this error on my server. Player lose their progress because of this error.

Sorry for my bad english. I'm new to this stuff so I don't really know how to fix it.

Code:

at java.lang.Thread.run(Thread.java:831) [?:?]
[14:42:21 ERROR]: Failed to save player data for Subiira
net.minecraft.server.v1_16_R3.ReportedException: Saving entity NBT
        at net.minecraft.server.v1_16_R3.Entity.save(Entity.java:1777) ~[patched_1.16.5.jar:git-Paper-775]
        at net.minecraft.server.v1_16_R3.WorldNBTStorage.save(WorldNBTStorage.java:37) ~[patched_1.16.5.jar:git-Paper-775]
        at net.minecraft.server.v1_16_R3.PlayerList.savePlayerFile(PlayerList.java:570) ~[patched_1.16.5.jar:git-Paper-775]
        at net.minecraft.server.v1_16_R3.PlayerList.disconnect(PlayerList.java:621) ~[patched_1.16.5.jar:git-Paper-775]
        at net.minecraft.server.v1_16_R3.PlayerConnection.a(PlayerConnection.java:1856) ~[patched_1.16.5.jar:git-Paper-775]
        at net.minecraft.server.v1_16_R3.NetworkManager.handleDisconnection(NetworkManager.java:520) ~[patched_1.16.5.jar:git-Paper-775]
        at net.minecraft.server.v1_16_R3.ServerConnection.c(ServerConnection.java:188) ~[patched_1.16.5.jar:git-Paper-775]
        at net.minecraft.server.v1_16_R3.MinecraftServer.b(MinecraftServer.java:1515) ~[patched_1.16.5.jar:git-Paper-775]
        at net.minecraft.server.v1_16_R3.DedicatedServer.b(DedicatedServer.java:436) ~[patched_1.16.5.jar:git-Paper-775]
        at net.minecraft.server.v1_16_R3.MinecraftServer.a(MinecraftServer.java:1342) ~[patched_1.16.5.jar:git-Paper-775]
        at net.minecraft.server.v1_16_R3.MinecraftServer.w(MinecraftServer.java:1130) ~[patched_1.16.5.jar:git-Paper-775]
        at net.minecraft.server.v1_16_R3.MinecraftServer.lambda$a$0(MinecraftServer.java:291) ~[patched_1.16.5.jar:git-Paper-775]
        at java.lang.Thread.run(Thread.java:831) [?:?]
Caused by: java.lang.NullPointerException: Cannot invoke "org.bukkit.World.getUID()" because the return value of "org.bukkit.Location.getWorld()" is null
        at net.minecraft.server.v1_16_R3.Entity.save(Entity.java:1757) ~[patched_1.16.5.jar:git-Paper-775]
        ... 12 more
Caused by: java.lang.NullPointerException: Cannot invoke "org.bukkit.World.getUID()" because the return value of "org.bukkit.Location.getWorld()" is null

 

i don't know what is the actual cause of this but i think this can happen if the player is at any invalid location like way far down the void (u can get there by using high level regeneration or God apples) or getting way up in the air in creative or any means and i remember way back i guess in any version of 1.14, teleporting to these type of locations (in offline world) used to kick u from the world and u can never log on to the world.
other reason can be that the files of the world at region where the specific player was present was got corrupted (world files are divided in many parts so whole can never get corrupted)