I don't get any error messages - in theory it's working - but the quality is appalling. Trying to watch the Arsenal - Galatasaray game now and it's so jerky and freezing literally every few seconds it's hopeless. BT, speak to Sky (or pretty much any other company that streams live video) and ask them how they do it, cos you've screwed up.
If you get these messages like I have then do the following;
1) Close your Internet browser 2) Go to 'control panel', 'date and time', 'Internet time' click change settings, uncheck box, click ok. Repeat but check box then click update now. If prompted error, click again and ignore if error comes up again, click ok. 3) Restart pc 4) login to bt sport and click yellow watch now button 5) 50/50 if works first time, if not 6) click yellow watch button again. Should work.
To avoid this problem recurring, each time you stop watching make sure you press the 'stop' button (escape to exit full screen, scroll arrow onto smaller screen, white square bottom left). This closes stream failure to do this means it remains classed as open.