Layout Blank in Page View

Had this happen a couple of times.

Whilst working on a vocal mock up I added a part (baritone). After which the full score is blank in page view but visible in gallery view.
Print view shows blank.
I created another full score Bottom of layouts and this behaves correctly.
I cannot find any issues (clearly missing something). Parts are selected and pages set to all.
Thanks Paul
60s Xmas.dorico (2.3 MB)

Your first full score layout has ended up without a page template set assigned to it, for some reason. Without a page template set, Dorico can’t generate pages.

The only thing I did to the score was to add a player. Very odd. Exact same thing happened to another score recently. I had thought it was a one off but evidently not.
Thanks for spot regarding template.

Is it possible you’ve updated your own saved defaults for full scores?