I frequently (but not always) have problems playing videos using Firefox, even though I can play them using Internet Explorer. Here's a case in point: https://www.nytimes.com/interactive/2017/10/26/climate/antarctica-glaciers-melt.html?emc=edit_ne_20171027&nl=evening-briefing&nlid=18949923&te=1&_r=0 The video plays with Internet Explorer, but when I go to the website using Firefox, the first frame of the video is shown with a rotating 8-spoked wheel in the center, but that's all that happens. I checked the help article "Fix video and audio playback problems on Firefox for Windows", but I have Windows 7 Home Premium, not Windows 7 N or KN.