skript region error

Exception in thread "Craft Scheduler Thread - 1382"
org.apache.commons.lang.UnhandledException: Plugin Skript v2.1.2 generated an exception while executing task 80
	at org.bukkit.craftbukkit.v1_7_R3.scheduler.CraftAsyncTask.run(CraftAsyncTask.java:56)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
	at java.lang.Thread.run(Thread.java:722)
Caused by: ch.njol.skript.SkriptAPIException: Serializer of region must override newInstance(), canBeInstantiated() or mustSyncDeserialization() if its class does not have a nullary constructor
	at ch.njol.skript.classes.Serializer.newInstance(Serializer.java:82)
	at ch.njol.yggdrasil.Yggdrasil.newInstance(Yggdrasil.java:340)
	at ch.njol.yggdrasil.Yggdrasil.isSerializable(Yggdrasil.java:154)
	at ch.njol.yggdrasil.YggdrasilOutputStream.writeGenericObject(YggdrasilOutputStream.java:169)
	at ch.njol.yggdrasil.YggdrasilOutputStream.writeObject(YggdrasilOutputStream.java:249)
	at ch.njol.skript.registrations.Classes.serialize(Classes.java:681)
	at ch.njol.skript.variables.FlatFileStorage.save(FlatFileStorage.java:423)
	at ch.njol.skript.variables.FlatFileStorage.saveVariables(FlatFileStorage.java:379)
	at ch.njol.skript.variables.FlatFileStorage$1.run(FlatFileStorage.java:200)
	at org.bukkit.craftbukkit.v1_7_R3.scheduler.CraftTask.run(CraftTask.java:67)
	at org.bukkit.craftbukkit.v1_7_R3.scheduler.CraftAsyncTask.run(CraftAsyncTask.java:53)
	... 3 more