Today I opened up Sibelius 6 - I use it everyday with VDL 2.5 - and all of the available devices and active devices were gone from the Playback Devices screen!  I saw that ";asianDRUMMER"; has a post on the same issue but it was never responded to. The only thing that I can think might have triggered this is that I installed some routine updates for my Macbook this morning.  That has never changed anything before though... Has anyone had this happen to them before?