Problem/Bug Can't start my server

The server was working nice till i added a login plugin, i deleted the playerdata content and its still not working

"internal server error"

Here is the error message:

Error Message (open) Error Message (close)

[20:49:40] [Server thread/WARN]: Failed to handle packet for /82.247.205.234:56618
java.lang.NullPointerException: null
at net.milkbowl.vault.permission.plugins.Permission_GroupManager.playerHas(Permission_GroupManager.java:104) ~[?:?]
at net.milkbowl.vault.permission.Permission.has(Permission.java:63) ~[?:?]
at net.milkbowl.vault.permission.Permission.playerHas(Permission.java:132) ~[?:?]
at com.sk89q.wepif.VaultResolver.hasPermission(VaultResolver.java:96) ~[?:?]
at com.sk89q.wepif.PermissionsResolverManager.hasPermission(PermissionsResolverManager.java:170) ~[?:?]
at com.sk89q.worldedit.bukkit.BukkitPlayer.hasPermission(BukkitPlayer.java:170) ~[?:?]
at java.util.stream.MatchOps$1MatchSink.accept(MatchOps.java:90) ~[?:1.8.0_72]
at java.util.Spliterators$IteratorSpliterator.tryAdvance(Spliterators.java:1812) ~[?:1.8.0_72]
at java.util.stream.ReferencePipeline.forEachWithCancel(ReferencePipeline.java:126) ~[?:1.8.0_72]
at java.util.stream.AbstractPipeline.copyIntoWithCancel(AbstractPipeline.java:498) ~[?:1.8.0_72]
at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:485) ~[?:1.8.0_72]
at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471) ~[?:1.8.0_72]
at java.util.stream.MatchOps$MatchOp.evaluateSequential(MatchOps.java:230) ~[?:1.8.0_72]
at java.util.stream.MatchOps$MatchOp.evaluateSequential(MatchOps.java:196) ~[?:1.8.0_72]
at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234) ~[?:1.8.0_72]
at java.util.stream.ReferencePipeline.anyMatch(ReferencePipeline.java:449) ~[?:1.8.0_72]
at com.sk89q.worldedit.command.util.PermissionCondition.lambda$satisfied$0(PermissionCondition.java:47) ~[?:?]
at java.util.Optional.map(Optional.java:215) ~[?:1.8.0_72]
at com.sk89q.worldedit.command.util.PermissionCondition.satisfied(PermissionCondition.java:47) ~[?:?]
at com.sk89q.worldedit.bukkit.BukkitCommandInspector.testPermission(BukkitCommandInspector.java:82) ~[?:?]
at com.sk89q.bukkit.util.DynamicPluginCommand.testPermissionSilent(DynamicPluginCommand.java:100) ~[?:?]
at org.bukkit.craftbukkit.v1_15_R1.command.BukkitCommandWrapper.test(BukkitCommandWrapper.java:39) ~[craftbukkit-1.15.2.jar:git-Bukkit-a81f6ed]
at org.bukkit.craftbukkit.v1_15_R1.command.BukkitCommandWrapper.test(BukkitCommandWrapper.java:1) ~[craftbukkit-1.15.2.jar:git-Bukkit-a81f6ed]
at com.mojang.brigadier.tree.CommandNode.canUse(CommandNode.java:78) ~[craftbukkit-1.15.2.jar:git-Bukkit-a81f6ed]
at net.minecraft.server.v1_15_R1.CommandDispatcher.a(CommandDispatcher.java:280) ~[craftbukkit-1.15.2.jar:git-Bukkit-a81f6ed]
at net.minecraft.server.v1_15_R1.CommandDispatcher.a(CommandDispatcher.java:254) ~[craftbukkit-1.15.2.jar:git-Bukkit-a81f6ed]
at net.minecraft.server.v1_15_R1.PlayerList.a(PlayerList.java:835) ~[craftbukkit-1.15.2.jar:git-Bukkit-a81f6ed]
at net.minecraft.server.v1_15_R1.PlayerList.d(PlayerList.java:686) ~[craftbukkit-1.15.2.jar:git-Bukkit-a81f6ed]
at net.minecraft.server.v1_15_R1.PlayerList.a(PlayerList.java:136) ~[craftbukkit-1.15.2.jar:git-Bukkit-a81f6ed]
at net.minecraft.server.v1_15_R1.LoginListener.c(LoginListener.java:126) ~[craftbukkit-1.15.2.jar:git-Bukkit-a81f6ed]
at net.minecraft.server.v1_15_R1.LoginListener.tick(LoginListener.java:53) ~[craftbukkit-1.15.2.jar:git-Bukkit-a81f6ed]
at net.minecraft.server.v1_15_R1.NetworkManager.a(NetworkManager.java:211) ~[craftbukkit-1.15.2.jar:git-Bukkit-a81f6ed]
at net.minecraft.server.v1_15_R1.ServerConnection.c(ServerConnection.java:122) [craftbukkit-1.15.2.jar:git-Bukkit-a81f6ed]
at net.minecraft.server.v1_15_R1.MinecraftServer.b(MinecraftServer.java:1037) [craftbukkit-1.15.2.jar:git-Bukkit-a81f6ed]
at net.minecraft.server.v1_15_R1.DedicatedServer.b(DedicatedServer.java:386) [craftbukkit-1.15.2.jar:git-Bukkit-a81f6ed]
at net.minecraft.server.v1_15_R1.MinecraftServer.a(MinecraftServer.java:940) [craftbukkit-1.15.2.jar:git-Bukkit-a81f6ed]
at net.minecraft.server.v1_15_R1.MinecraftServer.run(MinecraftServer.java:789) [craftbukkit-1.15.2.jar:git-Bukkit-a81f6ed]
at java.lang.Thread.run(Thread.java:745) [?:1.8.0_72]
[20:49:41] [Server thread/INFO]: Jonspleph lost connection: Internal server error
[20:49:41] [Server thread/ERROR]: Could not pass event PlayerQuitEvent to LoginSecurity v2.1.9
org.bukkit.event.EventException: null
at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:312) ~[craftbukkit-1.15.2.jar:git-Bukkit-a81f6ed]
at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:70) ~[craftbukkit-1.15.2.jar:git-Bukkit-a81f6ed]
at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:528) [craftbukkit-1.15.2.jar:git-Bukkit-a81f6ed]
at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:513) [craftbukkit-1.15.2.jar:git-Bukkit-a81f6ed]
at net.minecraft.server.v1_15_R1.PlayerList.disconnect(PlayerList.java:370) [craftbukkit-1.15.2.jar:git-Bukkit-a81f6ed]
at net.minecraft.server.v1_15_R1.PlayerConnection.a(PlayerConnection.java:1333) [craftbukkit-1.15.2.jar:git-Bukkit-a81f6ed]
at net.minecraft.server.v1_15_R1.NetworkManager.handleDisconnection(NetworkManager.java:306) [craftbukkit-1.15.2.jar:git-Bukkit-a81f6ed]
at net.minecraft.server.v1_15_R1.ServerConnection.c(ServerConnection.java:142) [craftbukkit-1.15.2.jar:git-Bukkit-a81f6ed]
at net.minecraft.server.v1_15_R1.MinecraftServer.b(MinecraftServer.java:1037) [craftbukkit-1.15.2.jar:git-Bukkit-a81f6ed]
at net.minecraft.server.v1_15_R1.DedicatedServer.b(DedicatedServer.java:386) [craftbukkit-1.15.2.jar:git-Bukkit-a81f6ed]
at net.minecraft.server.v1_15_R1.MinecraftServer.a(MinecraftServer.java:940) [craftbukkit-1.15.2.jar:git-Bukkit-a81f6ed]
at net.minecraft.server.v1_15_R1.MinecraftServer.run(MinecraftServer.java:789) [craftbukkit-1.15.2.jar:git-Bukkit-a81f6ed]
at java.lang.Thread.run(Thread.java:745) [?:1.8.0_72]
Caused by: java.lang.IllegalStateException: Can't retrieve player session from offline player!
at com.lenis0012.bukkit.loginsecurity.session.SessionManager.getPlayerSession(SessionManager.java:42) ~[?:?]
at com.lenis0012.bukkit.loginsecurity.modules.threading.ThreadingModule.onPlayerQuit(ThreadingModule.java:60) ~[?:?]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_72]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_72]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_72]
at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_72]
at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:310) ~[craftbukkit-1.15.2.jar:git-Bukkit-a81f6ed]
... 12 more
[20:49:41] [Server thread/INFO]: Jonspleph left the game
[20:49:41] [Server thread/WARN]: [Essentials] Task #46 for Essentials v2.17.2.0 generated an exception
java.lang.NullPointerException: null
at com.earth2me.essentials.xmpp.XMPPManager.updatePresence(XMPPManager.java:142) ~[?:?]
at com.earth2me.essentials.xmpp.EssentialsXMPP.updatePresence(EssentialsXMPP.java:113) ~[?:?]
at org.bukkit.craftbukkit.v1_15_R1.scheduler.CraftTask.run(CraftTask.java:77) ~[craftbukkit-1.15.2.jar:git-Bukkit-a81f6ed]
at org.bukkit.craftbukkit.v1_15_R1.scheduler.CraftScheduler.mainThreadHeartbeat(CraftScheduler.java:393) [craftbukkit-1.15.2.jar:git-Bukkit-a81f6ed]
at net.minecraft.server.v1_15_R1.MinecraftServer.b(MinecraftServer.java:985) [craftbukkit-1.15.2.jar:git-Bukkit-a81f6ed]
at net.minecraft.server.v1_15_R1.DedicatedServer.b(DedicatedServer.java:386) [craftbukkit-1.15.2.jar:git-Bukkit-a81f6ed]
at net.minecraft.server.v1_15_R1.MinecraftServer.a(MinecraftServer.java:940) [craftbukkit-1.15.2.jar:git-Bukkit-a81f6ed]
at net.minecraft.server.v1_15_R1.MinecraftServer.run(MinecraftServer.java:789) [craftbukkit-1.15.2.jar:git-Bukkit-a81f6ed]
at java.lang.Thread.run(Thread.java:745) [?:1.8.0_72]
[20:49:58] [WorldGuard Region I/O/INFO]: [WorldGuard] Region data changes made in 'world' have been background saved

Server is running 1.15.2
Thank you guys !