I had already read those steps posted by you to help someone else and carried them out before posting my SoS!! :-)
I followed those step by step, but the error still occurred. Like I said in my last post, I can work around the issue by setting the Audio (i.e. Microphone) to Off, but I feel there may be a proper fix for this.
I hope someone has come across this exact problem and offer me a long-term fix.