safari does not support html5 video player

Please disable all Safari extensions and test. If the problem is resolved, re-enable the extensions one or a few at a time until you find the culprit.

Hi Linc,

This worked for me in OS Sierra (10.12.1) and the culprits were the "Click to Plugin" and "Click to Flash" extensions.

Best regards

See if installing Flash Player helps. If not, uninstall it.

Adobe Flash Player

Adobe Flash Uninstaller

This worked for me. I have not yet isolated the conflicting extension