Mysterious, invisible clef?

Dear all,

I hope you can see my screenshot. The motive just underneath the tempo marking 115, plays back exactly the same as the motives before and after. It is supposed to be the same (it’s an ostinato) but why on earth does it appear to have changed clef? I imported this file from Sibelius as a XML…

Warm wishes!

XML import is always funky…

Do you have signposts on? And if so, are Signposts > Clefs on? If you have two hidden clefs there, they ought to show as signposts (little flags above the staff) if hidden.

Other than deleting and rewriting—does that even work?—it would help if you can post a cut-down of the project here for us to investigate.