I'm not conversant with the MAC version, but it looks like your vertical dimension is on a different workplane. Assuming that the MAC version is similar to the Win version, you could try deleting the dimension, selecting everything, and placing it all on the same workplane. Then redrawing the dimension.
You'll probably get a better answer on the TC-MAC forum.
TC21.2 x64 Plat, Bld59
TC16.2 Plat, Bld54.0