[09:08:57 INFO]: ttodgers issued server command: //undo
[09:08:57 ERROR]: An unexpected error while handling a WorldEdit command
java.lang.NullPointerException: The world was unloaded and the reference is unavailable
        at com.google.common.base.Preconditions.checkNotNull(Preconditions.java:787) ~[core.jar:git-Spigot-1a3504a-84f3da3]
        at com.sk89q.worldedit.bukkit.BukkitWorld.getWorld(BukkitWorld.java:155) ~[?:?]
        at com.sk89q.worldedit.bukkit.BukkitWorld.getName(BukkitWorld.java:173) ~[?:?]
        at com.sk89q.worldedit.LocalSession.saveHistoryNegativeIndex(LocalSession.java:279) ~[?:?]
        at com.sk89q.worldedit.LocalSession.loadSessionHistoryFromDisk(LocalSession.java:217) ~[?:?]
        at com.sk89q.worldedit.LocalSession.undo(LocalSession.java:543) ~[?:?]
        at com.sk89q.worldedit.command.HistoryCommands.undo(HistoryCommands.java:86) ~[?:?]
        at com.sk89q.worldedit.command.HistoryCommandsRegistration.cmd$_undo(HistoryCommandsRegistration.java:146) ~[?:?]
        at org.enginehub.piston.CommandManager.execute(CommandManager.java:158) ~[?:?]
        at com.sk89q.worldedit.extension.platform.PlatformCommandManager.lambda$handleCommandOnCurrentThread$17(PlatformCommandManager.java:693) ~[?:?]
        at com.sk89q.worldedit.extension.platform.PlatformCommandManager.handleCommandTask(PlatformCommandManager.java:709) ~[?:?]
        at com.sk89q.worldedit.extension.platform.PlatformCommandManager.handleCommandOnCurrentThread(PlatformCommandManager.java:695) ~[?:?]
        at com.sk89q.worldedit.extension.platform.PlatformCommandManager.lambda$handleCommand$15(PlatformCommandManager.java:665) ~[?:?]
        at org.bukkit.craftbukkit.v1_13_R2.scheduler.CraftTask.run(CraftTask.java:81) [core.jar:git-Spigot-1a3504a-84f3da3]
        at org.bukkit.craftbukkit.v1_13_R2.scheduler.CraftAsyncTask.run(CraftAsyncTask.java:52) [core.jar:git-Spigot-1a3504a-84f3da3]
        at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) [?:1.8.0_241]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) [?:1.8.0_241]
        at java.lang.Thread.run(Unknown Source) [?:1.8.0_241]