NSSplitView and autolayout

Question

How should I use auto layout constrains inside NSSplitView subview?

My NSSplitView subview has 3 subview: topPane, tableCont

Answer 1

I found out that this error appears if I have toolbar in my window and control split view by any of this delegate methods:

splitView:constrainMinCoordinate:ofSubviewAt:   
splitView:constrainMaxCoordinate:ofSubviewAt:
splitView:shouldAdjustSizeOfSubview:

Solution was found in attaching toolbar to window in windowDidLoad.