This issue has been raised in the H5P forum: https://moodle.org/mod/forum/discuss.php?d=421149 

Setup

• Install the last version of mod_hvp: https://moodle.org/plugins/mod_hvp 
• Install the last version of tool_migratehvp2h5p: https://moodle.org/plugins/tool_migratehvp2h5p 

Steps to reproduce the error

1. Login as admin.
2. Create a course.
3. Add a mod_hvp activity. Upload the attached file and, IMPORTANT!!, "Save and return to course" (don't view the H5P content).
4. Access to the Site administration page and click the "Migrate content from mod_hvp to mod_h5pactivity" link.
5. Select the mod_hvp activity you've created and click the "Migrate" button.

Expected result

The activity is migrated correctly.

Current result

The following error is displayed:

Fatal error: Declaration of core_h5p\framework::fetchExternalData($url, $data = NULL, $blocking = true, $stream = NULL, $fulldata = false, $headers = Array, $files = Array) must be compatible with H5PFrameworkInterface::fetchExternalData($url, $data = NULL, $blocking = true, $stream = NULL, $fullData = false, $headers = Array, $files = Array, $method = 'POST') in moodle/h5p/classes/framework.php on line 36

Some extra comments:

• The first failing version is Moodle 3.11 (so it's working as expected in the Moodle 3.10 series).
• In MDL-69331, some changes were added, to validate any H5P package before saving it. From what I've seen, that's why it has started failing now: in previous versions, autoloader::register() wasn't called (so there were no conflicts with the H5P interfaces that has changed during the last months).