I was able to fix this issue. This is a bug with the version of H5P that is uploaded to wordpress and is installed when you click upgrade.
From what I can understand, H5P has a folder inside it called /h5p-php-library
This folder is its own github folder/project that is only linked to from the primary H5P Wordpress Github. When they created the most recent Wordpress version that you can upgrade to, they forgot to include the h5p-php-library folder. The developers probably didn’t even notice because they probably upgrade from the command line using git, not the easy way from the web interface novices like me use.
So to fix it:
- Go to https://github.com/h5p/h5p-php-library/releases and download the most recent version of the h5p-php-library folder.
- Upload that folder to your h5p plugin folder. (You will have an empty folder right where it will need to go)
When I followed those steps it solved all my problems. I will also try to fix the github ticket to draw their attention to the issue.
Edit: You will have to go through the same steps for the h5p-editor-php-library folder. https://github.com/h5p/h5p-editor-php-library/releases