Thanks to everyone for their inputs. After executing multiple passes to repair Creator NXT Pro with no success, I removed the software and re-installed it. I still encountered the same issue with not being able to add background audio. Rather than continuing to chase my tail, I succumbed to pursuing the known the working state for the Windows 8.1 environment, a $79 upgrade to NXT Pro 2. It felt like the money was being extorted from me by Roxio, but low and behold, it did work. It would have saved a lot of time if Roxio would have just come out and stated that NXT Pro was incompatible with Windows 8.1. I’m up and working again, but I can’t say I’m a happy customer.