1.4.7 TT error

2013-07-10 11:39:41 [SEVERE] [ForgeModLoader] A TileEntity type thermalexpansion
.transport.tileentity.TileTeleportEnergy at ultimate_world/4,762,100,-21524 has
throw an exception trying to write state. It will not persist. Report this to th
e mod author
java.lang.IllegalArgumentException: Empty string not allowed
        at cc.<init>(SourceFile:15)
        at bq.a(SourceFile:77)
        at thermalexpansion.transport.tileentity.TileTeleportRoot.b(TileTeleport
Root.java:376)
        at thermalexpansion.transport.tileentity.TileTeleportEnergy.b(TileTelepo
rtEnergy.java:201)
        at aam.a(ThreadedChunkLoader.java:361)
        at aam.a(ThreadedChunkLoader.java:212)
        at im.saveChunk(ThreadedChunkProvider.java:757)
        at im.a(ThreadedChunkProvider.java:833)
        at net.minecraft.server.MinecraftServer.doWorldTick(MinecraftServer.java
:543)
        at nallar.patched.server.PatchMinecraftServer$TickRunnable.run(PatchMine
craftServer.java:671)
        at nallar.tickthreading.minecraft.ThreadManager$1.run(ThreadManager.java
:43)
        at nallar.tickthreading.util.FakeServerThread.run(FakeServerThread.java:
16)