Check template, Check videos features broken

I installed FV Flowplayer Pro on our WordPress 4.5.2 site, and so far everything works great, except for Check template and Check videos on the settings page. The busy icons display for a second, but no information is displayed. Disabling all plugins and switching to the default WordPress theme does not help. On a newly created WordPress 4.5.2 site, same Theme version, and almost all of the same plugins which come with the theme, Check template and Check videos do work.

Entering the pro licence on the problem site, which is in the same row of features on the settings page as Check template and Check videos, also did not work, but when I pressed “save all changes” for another section of the settings page, the licence was applied, and the pro plugin was automatically installed, which on the newly created test site was an extra step in the pro upgrade process. Very strange!

Perhaps we can live with this issue if everything else works, perhaps not, but either way it’s disconcerting and makes it more difficult to trust the reliability of the plugin.

Any idea what is happening here? How to troubleshoot further?

Thanks,

Kirk