XDP11 Error?

[Acorn]

Well, it seems to have stopped, for the time being.
But, why should it happen in the first place?

Servers sometimes die or proxies get confused so they need resetting. If you have no resilience for fail-over then somewhere you have a single point of failure and you need staff to "switch it off and back on again".
Xara only promises 98% availability.

Why does you Xara Desktop application care? Well in the pop-up error the application was effectively being told that the on-line content had had an update, new content added or old content removed but is could not then access the changed material as it was sitting on the affected servers.

The catindex.txt file is a sort of hierarchical listing mechanism in each Cache folder to ensure your Cache contents align with the on-line content.
When your Desktop application runs, the catindex.txt file you had become catindex.old and a catindex.tmp is collated from your actual Cache content. When the operation has downloaded the thumbnails of the new content and the new catindex.txt file, I believe at this point old content that is not in the new catindex.txt file is deleted from your machine. I posit this as there used to be Calendar templates that just vanished and I have a lot of blanks in place on local content that used to be there.

The alignment has always been my worry, which is why I clone my Cache elsewhere.

Acorn