Can't edit H5P activity in Moodle

Windows server with IIS
Moodl 3.6.3+
PHP Version 7.2.14

mysql  Ver 5.7.23 

Latest H5P plugin for Moodle

Creating H5P activity works fine but when I later try to edit the activity, I get the following error: error/invalidhvp. 

Debug gets me this:

Debug info:
Error code: invalidhvp 

$a contents:

Stack trace:

  • line 494 of \lib\setuplib.php: moodle_exception thrown
  • line 182 of \mod\hvp\mod_form.php: call to print_error()
  • line 481 of \course\moodleform_mod.php: call to mod_hvp_mod_form->data_preprocessing()
  • line 199 of \local\metadata\context\module\classes\context_handler.php: call to moodleform_mod->set_data()
  • line 421 of \local\metadata\lib.php: call to metadatacontext_module\context_handler->coursemodule_standard_elements()
  • line 749 of \course\moodleform_mod.php: call to local_metadata_coursemodule_standard_elements()
  • line 737 of \course\moodleform_mod.php: call to moodleform_mod->plugin_extend_coursemodule_standard_elements()
  • line 118 of \mod\hvp\mod_form.php: call to moodleform_mod->standard_coursemodule_elements()
  • line 204 of \lib\formslib.php: call to mod_hvp_mod_form->definition()
  • line 99 of \course\moodleform_mod.php: call to moodleform->__construct()
  • line 141 of \course\modedit.php: call to moodleform_mod->__construct()

I've read somewhere that it could be related to curl and remote files access so I checked if it's installed and enabled. It is. PHP info says: 

cURL supportenabledcURL Information7.61.1 

I thought H5P plugin doesn't require remote files once all libraries are downloaded and installed.

Any advice would be appreceated.

Kind regards,