We have checked this through FireFox and the videos play as intended. Please go here and double check that your Flash player is enabled: https://helpx.adobe.com/flash-player.html
Also if possible can you please provide some of the videos you have opened and do not play so we can investigate this further? Thank you!SC commented
no videos will play for me in Firefox. I haven't tried another browser, but shouldn't have to. Yep, flash player is up to date. This has been an issue for almost a week.