For those posting earlier saying they've had a response from the tech team claiming the fault has been fixed. Wait and see, I've again got the error message at 6.00 watching ipl on sky sports mix using the now tv stick. I am seriously sick of this nonsense.
I had this fault so badly last Saturday I gave up on using the Now TV stick and switched to using my Chromecast Ultra,
everything has been perfect on that so it definitely seems to be a software fault and not a fault with Now TV's servers.