Installation and server related problems

Moodle 3.1 on centos 7, mysql 5.7. Brand new installation of h5p. Is there something else I have to go and download in order for this plugin to work? I am able to navigate through the entire create activity functionality but when I go to save and display, I get the following error:

Hey,
I'v got no Problems with uploading mp4 files, but somehow I can't upload WebM files.
WebM files are grayed out. 

I've set no restriction to fileformats on my wordpress site and I can upload WebM Files with the media manager just fine.

Can someone help?

Just updated to the latest version and everything below Tutorial/Example is empty.  Cannot add new content or edit existing ones.  Copy/paste buttons also hidden.