Permission to earn points cannot be overridden at other levels than system

[FMCorz]

This makes it very hard to override the permissions.

Workaround for enabling permissions for a specific role only.

1/ Go to Site administration > Users > Define roles
2/ Edit the role "Student"
3/ Look for the permission "block/xp:earnxp" and untick "Allow", and save.
4/ Go back to Site administration > Users > Define roles, and click "Add a new role"
5/ Select "Use role or archetype": "No role", and continue
6/ Use the following values:

• Short name: "canearnxp"
• Custom full name: "Can earn XP"
• Context types where this role may be assigned: System, Category, Course, Activity module
• Allow role assignments: Manager, Teacher
• Allow role overrides: [Nothing]
• Allow role switches: [Nothing]
  7/ Look for the permission "block/xp:earnxp" and select "Allow", and click "Create this role".

Then assign the role to the relevant users, in the relevant contexts.