Noel,

Many thanks for this. Wasn't using the 'Realtracks Picker' approach you mentioned, but instead right-clicked in Soloist track in mixer, then 'Select Realtracks' and 'Select Best Soloist Realtracks', which brings up a somewhat different selection layout to the one you attached, including the not-totally-obvious solo / band toggle icon.

However, even when using 'Realtracks Picker' approach I still have exactly the same problem! 'Use Internet' is on. Could understand it if none of the Realtrack solos worked, but only having trouble with some is decidedly odd.

Tried disconnecting anti-virus software in case this was causing problems. Next moves will be to set bb to run from 'C' drive in case the present arrangement of it running from different one might somehow be causing trouble, although all BIAB preferences are set correctly for current drive. Then will rename a file that does solo correctly to that of one that doesn't in case something strange going on with file structure, albeit probably somewhat unlikely. Other than that, any inspired ideas would be very welcome!