An empty H5P activity will generate an error

I found this via our monitoring:

Error: Uncaught exception 'Error' with message 'Call to a member function get_contextid() on bool' in /var/www/html/mod/h5pactivity/view.php:57

It appears that the H5P activity does not have any files associated to it, which causes the following error.

It looks like this can happen if the following happens:

1. Create a H5P activity
2. In administration disable the content type added to the activity
3. Use the duplicate, import or another backup and restore function to create a new copy of the activity.