NullPointerException when using passwd from web server

15:30:57 [INFO] Failed to create user!
15:30:57 [WARN] java.lang.NullPointerException
15:30:57 [WARN] at net.rymate.jpanel.PanelPlugin.onCommand(PanelPlugin.java:307)
15:30:57 [WARN] at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44)
15:30:57 [WARN] at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:141)
15:30:57 [WARN] at org.bukkit.craftbukkit.v1_11_R1.CraftServer.dispatchCommand(CraftServer.java:650)
15:30:57 [WARN] at net.rymate.jpanel.ConsoleSocket$1.run(ConsoleSocket.java:85)
15:30:57 [WARN] at org.bukkit.craftbukkit.v1_11_R1.scheduler.CraftTask.run(CraftTask.java:71)
15:30:57 [WARN] at org.bukkit.craftbukkit.v1_11_R1.scheduler.CraftScheduler.mainThreadHeartbeat(CraftScheduler.java:353)
15:30:57 [WARN] at net.minecraft.server.v1_11_R1.MinecraftServer.D(MinecraftServer.java:730)
15:30:57 [WARN] at net.minecraft.server.v1_11_R1.DedicatedServer.D(DedicatedServer.java:399)
15:30:57 [WARN] at net.minecraft.server.v1_11_R1.MinecraftServer.C(MinecraftServer.java:675)
15:30:57 [WARN] at net.minecraft.server.v1_11_R1.MinecraftServer.run(MinecraftServer.java:574)
15:30:57 [WARN] at java.lang.Thread.run(Unknown Source)