I tried to upload content from https://h5p.org/node/1135617 as h5p-file to a wordPress site and i got the following error code:
Internal Server Error (500)
Unable to interpret response.
Please check your error log.
Browsers console gave information about "Paused on exception" on the first line of script "h5p-hub-client.js".
Everything worked fine when I loaded the same content to Moodle. I deactivated all WordPress plugins and reactivated H5P-plugin but it did not help.