reload is breaking the dungeon world

[Enzo1702]

(List steps to reproduce, e.g.:

1. Create a new dungeon with /dxl create
2. Leave edit mode with /dxl leave
3. Reload plugin with /dxl reload
4. Return in the dungeon with /dxl edit [name]
5. The world has been changed to normal world

Expected behavior

Load the originally created world with /dxl edit /dxl test

Relevant configuration files

[18:18:52] [Server thread/INFO]: TheFirstEnzo issued server command: /dxl create 1
[18:18:52] [Server thread/INFO]: [DungeonsXL] Creating new map.
[18:18:52] [Server thread/INFO]: [DungeonsXL] Generating new world...
[18:18:52] [Server thread/ERROR]: No key layers in MapLike[{}]; No key structures in MapLike[{}]
[18:18:52] [Server thread/INFO]: [WorldGuard] (DXL_Edit_0) TNT ignition is PERMITTED.
[18:18:52] [Server thread/INFO]: [WorldGuard] (DXL_Edit_0) Lighters are PERMITTED.
[18:18:52] [Server thread/INFO]: [WorldGuard] (DXL_Edit_0) Lava fire is PERMITTED.
[18:18:52] [Server thread/INFO]: [WorldGuard] (DXL_Edit_0) Fire spread is UNRESTRICTED.
[18:18:52] [Server thread/INFO]: [WorldGuard] Loaded configuration for world 'DXL_Edit_0'
[18:18:52] [Server thread/INFO]: [DungeonsXL] World generation finished.
[18:18:59] [Server thread/INFO]: TheFirstEnzo issued server command: /dxl reload
[18:19:02] [Server thread/INFO]: TheFirstEnzo issued server command: /dungeonsxl reload -force
[18:19:03] [Server thread/INFO]: ThreadedAnvilChunkStorage (DXL_Edit_0): All chunks are saved
[18:19:03] [Server thread/INFO]: [DungeonsXL] Multi floor dungeons are not part of the range of functions of this build.
[18:19:07] [Server thread/WARN]: [DungeonsXL] Task #5828 for DungeonsXL v0.18-PRE-02 generated an exception
java.lang.NullPointerException: Cannot read the array length because "" is null
at de.erethon.dungeonsxl.util.commons.misc.FileUtil.copyDir(FileUtil.java:82) ~[?:?]
at de.erethon.dungeonsxl.world.DEditWorld$2.run(DEditWorld.java:180) ~[?:?]
at org.bukkit.craftbukkit.v1_16_R3.scheduler.CraftTask.run(CraftTask.java:81) ~[server.jar:3096a-Spigot-9fb885e-af1a232]
at org.bukkit.craftbukkit.v1_16_R3.scheduler.CraftScheduler.mainThreadHeartbeat(CraftScheduler.java:400) ~[server.jar:3096a-Spigot-9fb885e-af1a232]
at net.minecraft.server.v1_16_R3.MinecraftServer.b(MinecraftServer.java:1179) ~[server.jar:3096a-Spigot-9fb885e-af1a232]
at net.minecraft.server.v1_16_R3.DedicatedServer.b(DedicatedServer.java:394) ~[server.jar:3096a-Spigot-9fb885e-af1a232]
at net.minecraft.server.v1_16_R3.MinecraftServer.a(MinecraftServer.java:1127) ~[server.jar:3096a-Spigot-9fb885e-af1a232]
at net.minecraft.server.v1_16_R3.MinecraftServer.w(MinecraftServer.java:966) ~[server.jar:3096a-Spigot-9fb885e-af1a232]
at net.minecraft.server.v1_16_R3.MinecraftServer.lambda$0(MinecraftServer.java:273) ~[server.jar:3096a-Spigot-9fb885e-af1a232]
at java.lang.Thread.run(Thread.java:831) [?:?]
[18:19:09] [Server thread/INFO]: TheFirstEnzo issued server command: /dxl edit 1
[18:19:17] [Server thread/INFO]: [WorldGuard] (DXL_Edit_1) TNT ignition is PERMITTED.
[18:19:17] [Server thread/INFO]: [WorldGuard] (DXL_Edit_1) Lighters are PERMITTED.
[18:19:17] [Server thread/INFO]: [WorldGuard] (DXL_Edit_1) Lava fire is PERMITTED.
[18:19:17] [Server thread/INFO]: [WorldGuard] (DXL_Edit_1) Fire spread is UNRESTRICTED.
[18:19:17] [Server thread/INFO]: [WorldGuard] Loaded configuration for world 'DXL_Edit_1'
[18:19:17] [Server thread/WARN]: Can't keep up! Is the server overloaded? Running 7563ms or 151 ticks behind