//up throws java.lang.IllegalStateException: Asynchronous block remove!

[U1F984]

//up doesn't work as expected:

[16:06:52 INFO]: Player issued server command: //up 1
[16:06:52 ERROR]: [WorldEdit] An unexpected error while handling a WorldEdit command
java.lang.reflect.InvocationTargetException
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_72-internal]
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_72-internal]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_72-internal]
        at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_72-internal]
        at com.sk89q.worldedit.util.command.parametric.ParametricCallable.call(ParametricCallable.java:243) ~[worldedit-bukkit-6.1.1-SNAPSHOT-dist.jar:?]
        at com.sk89q.worldedit.util.command.SimpleDispatcher.call(SimpleDispatcher.java:125) ~[worldedit-bukkit-6.1.1-SNAPSHOT-dist.jar:?]
        at com.sk89q.worldedit.extension.platform.CommandManager$1.run(CommandManager.java:253) [FastAsyncWorldEdit.jar:?]
        at org.bukkit.craftbukkit.v1_8_R3.scheduler.CraftTask.run(CraftTask.java:71) [server.jar:git-Spigot-5f38d38-18fbb24]
        at org.bukkit.craftbukkit.v1_8_R3.scheduler.CraftAsyncTask.run(CraftAsyncTask.java:53) [server.jar:git-Spigot-5f38d38-18fbb24]
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [?:1.8.0_72-internal]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [?:1.8.0_72-internal]
        at java.lang.Thread.run(Thread.java:745) [?:1.8.0_72-internal]
Caused by: java.lang.IllegalStateException: Asynchronous block remove!
        at org.spigotmc.AsyncCatcher.catchOp(AsyncCatcher.java:14) ~[server.jar:git-Spigot-5f38d38-18fbb24]
        at net.minecraft.server.v1_8_R3.Block.remove(Block.java:317) ~[server.jar:git-Spigot-5f38d38-18fbb24]
        at net.minecraft.server.v1_8_R3.Chunk.a(Chunk.java:536) ~[server.jar:git-Spigot-5f38d38-18fbb24]
        at net.minecraft.server.v1_8_R3.World.setTypeAndData(World.java:396) ~[server.jar:git-Spigot-5f38d38-18fbb24]
        at org.bukkit.craftbukkit.v1_8_R3.block.CraftBlock.setTypeIdAndData(CraftBlock.java:137) ~[server.jar:git-Spigot-5f38d38-18fbb24]
        at com.sk89q.worldedit.bukkit.adapter.impl.Spigot_v1_8_R3.setBlock(Spigot_v1_8_R3.java:237) ~[?:?]
        at com.sk89q.worldedit.bukkit.BukkitWorld.setBlock(BukkitWorld.java:416) ~[?:?]
        at com.sk89q.worldedit.world.AbstractWorld.setBlock(AbstractWorld.java:83) ~[?:?]
        at com.sk89q.worldedit.world.AbstractWorld.setBlockType(AbstractWorld.java:58) ~[?:?]
        at com.sk89q.worldedit.extension.platform.AbstractPlayerActor.floatAt(AbstractPlayerActor.java:304) ~[?:?]
        at com.sk89q.worldedit.extension.platform.AbstractPlayerActor.ascendUpwards(AbstractPlayerActor.java:292) ~[?:?]
        at com.sk89q.worldedit.command.NavigationCommands.up(NavigationCommands.java:181) ~[?:?]
        ... 12 more