Compressed (zipped) folder is empty

[SimonB27P]

I have tried to download the parts library three times on two different computers and everytime when I try to extract the zip file I get the message the Windows "Cannot complete the Compressed (zipped) Folders Extraction Wizard" because

"The compressed (zipped) folder is empty.

Before you can extract files you must copy files to this compressed(zipped) folder"

The folder is showing as taking up 3.6GB on may hard drive. I'm a bit baffled by this. Is this a recent issue? Or is anyone else having this problem?