Problems changing stream resolution - no available tuners

[Nathanio 35]

I am running Emby  3.0.5781.1 and 2 HD HomeRun HDHR24-2DT(total of 4 possible streams). If I am streaming on a web client a SD channel it defaults to 1080p so is squashed up. I go to change to 480p and get an error Video Error. There was an error playing the video. Please ensure there is an open tuner available. 

 

I've got no other streams open at this time so surely it should jump to another open tuner and continue?

 

Attached are the logs and screenshot of the error

 

Thanks

 

server-63583958804.txt