The "Move File" operation will not allow you to change the name so the destination can only contain a path to the file folder without the file name. If you want to move it and give it a different name at the same time then you need to use the "Rename File" operation. It was confusing to me at first and I still don't understand why they chose to give this functionality to the "Rename File" operation instead of giving it to the "Move File" one or even create another called something like "Move and Rename File".