I'm launching a site and thought I had all the bases covered until I discovered the video(s) could not be seen on an Android HFC or some acronym I can't remember now. Really blew me away since I went to Vimeo (paid version) instead of using YouTube for these intro videos. It could be resolved by now (too early to bug friends and family) as there is an option for paying members at Vimeo to upgrade videos to play on mobile in what they describe as:
"Enabling this option will convert this video to format optimized for mobile playback on supported devices."
Ha, supported devices! The videos have always worked fine on my Ipad, but now I get this surprise out of the dark.
Please check. Like I said, the problem could be resolved. If you do have problems please list the devices used.