Hi Simon,

many thanks for your reply. I thought I'd start with blank BIAB track, chose a basic blues style with 4 tracks, 12 bars, 2 choruses - something very simple. The songs I generally use are 10+ years old, they just keep getting slightly modified and saved with each new BIAB version. No utility, melody or any other solo tracks, just purely accompaniment.

I tested it out with basic Windows audio and then also with ASIO and additional VST3 tracks for guitar plug-ins - and, surprise, it worked perfectly for both This Page and All Pages. Excellent!

Hard to say what went wrong the first time, perhaps the SGU had an issue, or something within Reaper or the plug-in config - I did read the manual and looked at some of videos/tutorials and made a couple of changes.

Cool, no further help required but will get back to you, perhaps via the PG Music support line, if I have any other issues in the future. Cheers, Paul