
I deleted one of the device entries - so we got to watch the program (10 minutes later, while SWMBO sat there wondering what the hell I was doing and losing patience with my grumbling as I eventually figured it out). It may have caused me to mutter expletives about Lightbox.
I think I read of some technical "reasons" why this could happen (browser updates?). Checked by logging in on the MBP, and sure enough, the "too many devices" error, and also the "Cannot unregister more devices" message - as I'd used my one opportunity in 30 days.
So that's it. Hopefully someone from lightbox will respond to this to advise that they've fixed this problem. If there's a "simple fix for a known issue" - then it should be clearly displayed on the page that the above image was taken from. I'm not feeling inclined to want to search google, read FAQs or phone help desks in order to sort out a problem which is not of my making. I've seen the entire "Better Call Saul" series 1. I'm inclined to want to just cancel my subscription.