At last! I get a corrupt file - terrific.. And of course it's a VERY IMPORTANT ONE!
Basically an entire days (paying) work down the drain. Strangely even the .BAK won't open.

As is normal for me, I save regularly, usually after every successful operation, or before I'm about to attempt something that could cause Xara to complain.

It was during the (final, as it turned out) Save that Xara complained there was an "error while saving".. Nothing else.

I couldn't even close the error box via the OK button or the [X].
Before I terminated Xara via Taskmanager, I made a second copy of the file.

As expected, Xara couldn't open the file and after a few seconds just froze.

Next came EXPANDXAR.EXE.

Trying this was curious.
The .xar file is 1.8mb - yet the EXPANDXAR process was expanding a 'fixed.xar' of enormous size! I actually had to stop the process (Ctrl+Break) at 2.5GB. Yes 2.4 Gigabytes!

Needless to say, Xara can't open that one either.

Has anyone else come across this problem with EXPANDXAR simply expanding and expanding forever?

I'd post the file here for others to try if it weren't a private client file.
So it looks like I'm destined to redo the entire work...

sigh