After being away for a couple of months ... I was able to copy a map with 4 layers in it, and need to add another existing dataset.  The '+' icon to add another dataset is absent from the top of the layer management on the right side.  It is also absent from the original map.
Do I have something locked?
(I am on a 'free' license)
          
أكثر...
			
			Do I have something locked?
(I am on a 'free' license)
أكثر...