Understood. I see the same behavior with Pages. I guess I'll need to add an 'Export To' instead. Thanks for your help.

Thank you for your help! Is there anyway, to have that menu option permanently available? (It is a very common operation in this app, and my original AppKit native version worked this way - this is my first SwiftUI app). The Save panel does not appear when I press Save - it does when I use Save As. It appears to be using "auto save" (I have another ticket asking how to disable this).

Did you every figure this out? Apple support is painful - I guess the only way to get a response is to file developer bug tickets.

It is crazy that you can't at a crash even figure out the element that SwiftUI was trying to render... I am having a similar issue when using 'delete' in List of a ForEach - the SwiftUI framework is calling back into my collection using an index - but the index doesn't exist because it was deleted. It shouldn't be using the index anyway - as the backing data structure is Indentifiable and Hashable.