“[something copyWithZone:]: unrecognized selector sent to instance” when using Bindings / Core Data

Question

(self asking and self-answering because I spent hours on the web looking for this, and most of the resources all say \"I solved it in the end\" without giving an explanation

Answer 1

I got this when I returned a view from the NSTableViewDataSource function -tableView:objectValueForTableColumn:row:. Instead, it is supposed to return a value (e.g. NSString*). (Not surprising given its name, but the error is not helpful in discovering this. The function I was thinking of is -tableView:viewForTableColumn:row: in NSTableViewDelegate.)