When I try to record from digitaltheatreplus.com, I get the message: "Jaksta Media Record: Stream added." Then within half a second there's another message that "Jaksta Media Recorder quit unexpectedly." JMR keeps quitting for any file I've tried on the site.
I'm running JMR Version 2.2.3 (261) on Mac OSX Version 10.12.6.
I have quickly tested that site and I too had Jaksta crash shortly after the video started playing. I think it is safe to say that this is due to a change made to the site that Jaksta reacts badly to, and it will require a fix.
I will add it to our development list, but we have some other high priority issues we are currently working on so no ETA as to when it will be ready. If it's easy enough then we might be able to get the fix bundled into the next update, which should be in the next week or two.