Problem with 1 Mac (out of 4 different Macs) having issue connecting to Airplay
I have not been able to fix the problem, after about 3 hours of trying. 

Fortunately i found a work around which is Airparrot, it seems slightly counter intuitive to use a 3rd party app to run an native OSX function when speaking to another Apple product, but it works really well on the machine i was having an issue with.