I got this error after trying to check all the Views available (just defaults as I get used to the new Dataform activity type).

Exception - Call to a member function get_view_patterns() on null

And the 'More information about this error' link led me to https://docs.moodle.org/35/en/error/moodle/generalexceptionmessage.

I was expecting to see my two example entries displayed in 'Grid' View.