Blank Page when Adding User or Updating a User Password

We are on Moodle 3.3, with H5P 1.5. We've had some issues with H5P so we uninstalled, updated Moodle to 3.3 from 3.2, and then reinstalled H5P and now it works well except for two things.

When an instructor adds a new user or updates a user's password, she gets blank page. However, when she checks to see if the new user is there, or if the new password works, they are fine. She just isn't seeing any confirmation message or page - just that blank page. 

Everything else in H5P seems to be working fine.

Any suggestions welcome.