If you are getting an "Invalid Scope" message in Canvas you may have Enforce Scopes turned on which can affect Badgr's ability to run.
To solve this, in Canvas go to the Admin menu and select the sub-account or root level of your instance. Select the Developer Key menu in the left-hand sitewide navigation of the Canvas instance. Find and edit the Badgr Developer Key and toggle the Enforce Scopes setting to the "off" setting. Save the changes and check the course to see if Badgr is now enabled. If you don't see one for Badgr, you may need to select the Show All Keys button at the bottom of the list.