This is amazing!!! I ran into this issue yesterday and I've spent some hours today to isolate this weird NavigationSplitView behaviour to the presence of a ToolbarItem in the bottom bar. And now seeing your workaround being posted 4 hours earlier is mind blowing! Thanks @domagojbu, you've saved my design!

Yes!!! Thank you, it worked! I did try that before in various places in Xcodes build-settings itself but it never worked. But with your tip of putting it into a xcconfig in the CorePlot project it worked. That is the most confusing thing: getting an error like this in one file and not in my own code that is written in similar way...

I like it when I, just by writing the question, answers myself... 😀Of course I have to programmatically add the constraints myself and after reading up on how, it was easily solved.So if there is anyone finding this post in search for something similar, this is how I did it:Constrained the top, left and right sides of the view I was inserting to the top, left and right sides to the contentView of the table cell.Then constrained the bottom of the contentView to the bottom of the inserted view.This makes the view follow the width of the table cell and layout its content regarding this constraints. And the height of the cell is now dependent on the intrinsic size of the inserted view.Just make sure that the inserted view is set to use Autolayout and all the constraints within it adds up.Thanks for listening.