Having set casting off to 4 bars it’s overwritten by adding a pickup bar and destroys the layout. I don’t have time to check it up at the moment but I guess there’s some setting in the casting off that needs to be changed? Need I say it’s annoying…
Pickup bar overwrites casting off.dorico (1.4 MB)
Is my issue related to this?
Clearly, something has gone wrong, and it may be a bug, but you don’t actually have a pickup bar in that document that I can see.
Deleting your initial time sig seems to fix it, revealing a pickup bar, and barring in the correct place.
I’m unable to reproduce the problem by creating a new pickup bar in an existing run of “whole” bars.
Edit: By adding another instrument, I can see what went wrong: it looks like you’ve created a LOCAL time signature on top of the global time sig with the pickup.
That explains why deleting the time sig revealed another time sig with the correct pickup.
I might have been a bit unclear and in a hurry when posting a file without a pickup bar. But since this file was a copy of the original, how could I have known that it would disappear by readding a pickup bar.
Here’s the file with a pickup bar and notes in it.
I have only changed the pitches to keep my copyright safe. 
And how did I do that? I don’t know how to do that.
It is when you, when creating a new upbeat or time signature, hit the alt/option key together on purpose or by accident.
I didn’t do it on purpose, that’s for sure.
So I must assume that it’s common practice to have those open measures without a barline at the end of systems when creating local time signatures?
If the local time signature is a different metre, or has a different pick-up “offset” from the global metre, then yes, you’re going to bars cut in half where they don’t coincide with the global metre.
