Need Help! "Error, unable to load libraries"

I have  h5P projects that display properly in my WordPress multisite, but when I try to edit them, I get the "Error, unable to load libraries" message. I get the same message whenever I click on my H5P "Libraries" link. I'm using the most recent version of the H5P plugin, WP 5.2.4 and PHP 7.2.23. If I need to reinstall the plugin, how do I keep a copy of my projects? I do not have the "download" button activated.