I am trying to attach a rubric to an assignment and the Add Rubric button is missing. I was able ...

I am trying to attach a rubric to an assignment and the Add Rubric button is missing. I was able to attach previously rubrics in my course, but now I am unable to. What would be the cause(s) for this, and how would I correct this? Please and thank you!
 

I have read through other forums and there was mention of the Competencies Tool being turned on/off. We recently acquired Brightspace as our new LMS and are still organizing our instance, and I was just informed that it has been turned off. Would this be the reason? If so, the Competencies check box in rubrics is still available and checked. And to clarify if this is the cause, is there a way around being able to use Rubrics without the Competencies tool?