Q: Interface Builder and NSTableView top constraint I have the following UI definition:

I wanted to define the constraints for the components but whenever I try to add a constraint so that the Bordered Scroll View - Table View.top is topStackView.bottom + 20, I get a constraint conflict. There is a hidden constraint where the Bordered Scroll View - Table View.t must be
topStackView.bottom + 8.
So, my question is where is this +8 constraint coming from? I assume it must be from the NSScrollView that contains the table as all the components inside seem to have Translate Masks Into Constraints.
How can I properly use Auto Layout so achieve what I want?

A: I haven't done much with MacOS apps, but this may solve your issue...
Delete the Bordered Scroll View - Table View.top is topStackView.bottom + 20 that you're trying to add.
You have them embedded in a vertical stack view - mainStackView - so set the Spacing on that stack view to 20.
It may not look right in Storyboard / IB, but the result should be correct (I have two buttons at the top, but that won't make a difference):

