@ClintBrown3D
A quick follow up. I tried to create a new drawing from a sketch, and now I'm able to access the manage tab and attributes. However, this is not what I'm looking for. I want to create a drawing template with this attributes. If I click "New Drawing Template", all this Manage extension options disappears.
UPDATE:
For some very strange reason this solved itself. When I first tried to open a new drawing template, none of the Manage attributes was accessible (as shown in the first post). Then I tried to create a new drawing form a existing design and then went into edit title blocks and added a new attribute, all the Manage extensions where accessible. Then I went back and created a new drawing template once more, and now I have all the attributes available.
Don't know why, but this solved the problem.