I'm on Vegas 12 (build 770) on my brand new INSANE Skylake/Windows 10 system. 64GB ram, 4 TB SSD array, 64TB HDD array.
I have created an Audio CD project in Vegas (as I always have before) but when going to Tools... Burn Disc... Disc At Once, Vegas does not detect my CD Burner.
It's an LG WH12LS38 Blu-Ray/DVD/CD Writer. Windows sees it fine, as does Nero. I'm able to burn fine in other applications.
I've tried every combination of check marks on the Options...Preferences...CD Settings tab, nothing gets it to see the drive.
The worst part is that there's no other way to export this project and maintain track-splits where I've set them. There's no "Burn to ISO" that will at least let me save it to disk and then burn it in Nero.
In years past it was usually the Nero drivers that caused problems. I had no use for Nero and removed it. You may have a use for Nero, so I only mention this if you needed something to try. Back then it was how Nero hooked in with a filter driver that did not always pass through control to other applications that needed to access the drive.