Sue, I am sorry you have had these problems. I cannot address why you are getting these issues.
The "Error, failed to copy the XAR file's support folder." could be just that and you have a bad sector on your hard disk.
Full uploads and changes not happening are usually signs of publishing to the wrong server location.
You should re-install v18 and engage with Xara directly; you can run v17 and v18 side-by-side.
Acorn
Bookmarks