Menu not showing. Potential bug resolved!

We have discovered a potential bug in the H5P plugin.
It seems to us that `H5P_Plugin::assign_capabilities()` only runs when upgrading from an older version, or when switching from single-site to multi-site or vice versa.
This means that if you have a fresh install, the capabilities will never be set properly, leading to the menu item for H5P not showing up and users not getting the correct permissions.

Best regards

Bjorn @