The pop-up dialogs typically keep the OK button grayed out until the required information has been entered. Understandable, the issue that I'm seeing is that even after the information has been input it does not offer the OK button as it should. If I go back into the model area and "shake my model" (rotate) the Pop-UP GUI will wake up and offer the OK button. I've seen this in several pop-up dialogs, so I doubt it is specific to the pop-up.
Simple example that should recreate the issue.
Start a New Design
Change Units from default to some other units.
You can move your mouse around with no affect, but if you use an action to move the model (pan or rotate) the OK button will become active.
MacBook Pro (Retina, 15in, Mid 2015), 10.14.6 Mojave, 2.8GHz i7, 16GB, AMD R9 370X
Fusion
