I have recently tried using the rosetube YouTube to view on my TV. I can no longer view it on my main TV. When I am at the unit which is a Rose 150b I can see the video on the Rose but when I try to touch the screen where you it says TV to switch from the Rose screen to the TV, I get an error "HDMI function is not ready for use. Please check the HDMI connection status”. The resolution is set at the 4k output but I did try all of the other settings just see if any of them would work. The function had worked in the past and never had any issues. Is there some other setting that I am not aware of? There have been a number of large updates since I have used the audio/video function so perhaps something may have changed.
Did you try the search on this forum. I have seen this before Somewhere.
Did you remove the HDMI cable? It often works to reintroduce a connection to a system. Take the cable off the Rose, restart and then plug in the HDMI from the tv. This reinitializes the connection.
I never had any problems with the HDMI output. I use it only for the video, not sound. Sound goes to my external DAC or to my Amp.