I'm really sorry to hear about the problems you're experiencing with your On Demand service lately.
What are you having trouble watching? The 319 error is a general one and is a symptom of a few individual issues at the moment. I wouldn't expect it to last very long as the team are working on getting this resolved as soon as possible.
Apologies for the inconvenience this is causing, if you continued to experience issues for much longer, let us know what you're experiencing issues with and I'll take another look for you right away.
Still got this problem, not just with DC's Legends of tomorrow, but any OD service to watch. As for the Link+ which I used to record Legends (as my Tivo box decided not to record this series) it recorded Idiot Abroad and claims it's Legends of Tomorrow!!!
Craig_D is away at the moment so I hope you don't mind me stepping in.
Regarding the 319 error code this should only be affecting content from Channel 4 and Sky so are the programs you're trying to view from these channels?
I have checked your boxes and both look fine so I think it may be to do with the outage we have going on at the moment but if it's programs outside of those channels please let me know so I can investigate this further.