I'll have to try and sort out that ... bugger !!

Well ... that was easy. Everything's working fine this morning - no need for me to take any action at all.

I have no idea what was going on. The error message's reference to a ".tgz" file instead of the more usual ".tar.gz" is a little suspicious.
I'm guessing the web hosting company did something that led to the problem ... and then subsequently un-did it.
No good asking them about that - they're as secretive as a national security organisation, and as ruthless faik.

Cheers,
Rob