Hey croxis i got this error with the lift plugin. Only on "Multi passenger elevators " u found a way to fix it?

23:54:09 [WARNUNG] [Lift] Task #31417 for Lift v29 generated an exception java.util.ConcurrentModificationException at java.util.HashMap$HashIterator.nextEntry(HashMap.java:810) at java.util.HashMap$KeyIterator.next(HashMap.java:845) at net.croxis.plugins.lift.ElevatorManager.endLift(ElevatorManager.java:179) at net.croxis.plugins.lift.ElevatorManager.run(ElevatorManager.java:268) at org.bukkit.craftbukkit.scheduler.CraftTask.run(CraftTask.java:53) at org.bukkit.craftbukkit.scheduler.CraftScheduler.mainThreadHeartbeat(CraftScheduler.java:345) at net.minecraft.server.MinecraftServer.r(MinecraftServer.java:529) at net.minecraft.server.DedicatedServer.r(DedicatedServer.java:222) at net.minecraft.server.MinecraftServer.q(MinecraftServer.java:493) at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:426) at net.minecraft.server.ThreadServerApplication.run(SourceFile:856)