For some reason World Edit has changed the commands for saving, loading, copying and pasting schematics.

Now commands like //save won't work, instead you have to do commands like:

[Select region]
//copy
//schematic save mce <name>
//schematic load mce <name>
//schematic paste

The format has changed, so that mce stands for MC Edit
//clear clears the clipboard.

>>>>>>>>>>HERE<<<<<<<<<<

I think that it is much more complicated like this but I am sure that they have a reason for it.
I hope that this has been helpful!

-M