Sibelius do playback but export nothing during export.
New Ideas : Sibelius Feedback Community 2016-01-26
Summary:
I've found a very annoying issue with Both Sibelius 7.x and Sibelius 8.1 on El Capitan: Sometimes, for some certain project file, while I was trying to export them to audio files, Sibelius play the music as the output progress bar increases and finally exported nothing onto my hard disk. P.S. This bug exists for really long time and some other users encountered this bug with Sibelius 6.