I'm having mostly consistent problems with the videos. They vary between not progressing at all, or lagging significantly behind the audio - often missing bits as the video catches up after a pause. If I rewind a bit, they'll generally play better - but usually not perfectly. This is detracting significantly from the material, as often the animations lag behind the narrative, and bits are missing altogether - unless I rewind for another look which interrupts the flow. Any suggestions ? I'm using Firefox (64bit, version 77), running on a Mabbook Pro with OS X 10.10.5 (Yosemite) which is the most up to date the hardware supports. It's been happening across all the modules I've done so far.

Hi Simon! Thanks for reaching out. We are sorry for this inconvenience. Can you please try using another browser? If you've tried that, does the issue persist? Thank you. Hope this helps.Best,Martin

Safari doesn't even show the video pane - just the subject heading. Chrome does play the videos properly, but I try and avoid using it due to the way it keeps wanting to take over the system - always installing startup items I don't want. Not to mention Google being second only to Facebook for stalking users. PS - shouldn't I get an email notification when there's a reply to my question ? Simon