After condensing 2 flute parts into one, the trill line has dissapeared. I have checked the 2 parts and there the trill line is present. I presume this is a bug. Is there any way I can solve this?
I have another question. If I want to change a condensed part or add something to it, do I always have to go back to the uncondensed version? Or is there a way to write in a condensed version?
Best,
Bert
#2 There is no way to change notes, etc. in a condensed part other than going back to uncondensed lines to make any change.
Instead of going back to the uncondensed version, you can also switch to Galley View. If you do, all the parts will always be viewed on separate staves regardless if condensing is activated or not. When switching back to Page View, you will see that all you changes to the layout will be preserved.
Thanks, that is very helpful! Will the problem with the trill line solved in a next version? I need it to work when I want to publish the score! 
Bert, there are some problems with trills in condensing, but they are normally along the lines of the auxiliary note appearing incorrectly, rather than the trill not appearing at all. Please make a copy of your score (using File > Save As) and delete all of the players aside from the flutes, all of the bars except for those including the trills, and then attach that version here so we can take a look and see what might be up.
Project Appermont (flute trill issue).dorico (2.3 MB)
Hi Daniel,
I have attached the file. As you can see, in the full score (condensed version) the flute trill has no trill line.
Best,
Bert
The property for the trill line to appear is set locally, you need to set it also in the condensed staff in Engrave mode.
That is the solution! Many thanks, Dorico is amazing!