Eventually with some difficulty I solved this problem. To make sure that the accessory panel is loaded from the .xib I do this: IBOutlet NSView* accessoryView; if(!accessoryView){ //not loaded yet         NSArray *_Nullable* topLevelObjects = nil; //allocated as nil but doing it explicitly supresses a compiler warning         if([[NSBundle mainBundle] loadNibNamed: @"accessoryView" owner: self topLevelObjects: topLevelObjects] == NO){             myCustomAlert(@"INTERNAL ERROR!", @"Unable to load accessory popup menu xib in Save as dialog.");             return;         }     } I encountered a strange error. If I provide the NSSavePanel with a list of fileTypes like this: NSArray * fileTypes = [NSArray arrayWithObjects: @".tiff", @".pdf", @".jpg", @".png", @".jp2", @".bmp", @".insc", nil]; [savePanel setAllowedFileTypes: fileTypes]; The savePanel will encounter an error when I run it with [NSSavePanel runModal]; When the user selects a different file type from the accessoryView popup menu in the NSSavePanel the method that is executed just does this: [savePanel setAllowedFileTypes: [NSArray arrayWithObject: [[[sender selectedItem] title] lowercaseString]]]; This changes the file extension when the panel is running modal.

I have the same problem, also the code: NSBundle *mainBundle = [NSBundle mainBundle]; NSURL *receiptURL = [mainBundle URLForResource: @"receipt" withExtension: @""]; receiptData = [NSData dataWithContentsOfURL: receiptURL options: NSDataReadingMappedAlways error: &theError]; crashes without logging any errors in the console pane in XCode or the console when I use the dataWithContentsOfURL method and then I start to get all of the application is damaged alerts. How can you test your receipt validation code with this bug? You should file a bug report. Also there are other threads about this.

It started to work again. The debug app isn't crashing when I call the method: URL *receiptURL = [mainBundle URLForResource: @"receipt" withExtension: @""]; anymore and when the receipt validation code calls exit(173), XCode relaunches the app with a dialog for me to enter my test user ID and password, and adds a valid receipt. This MIGHT be because I added a build phase to the target: Copy Files Destination - Wrapper Subpath - @"Contents/_MASReceipt/receipt" If you get the same errors that I did, try the above. Maybe it will solve this problem.

Six months ago and you haven't solved the problem? Apple DTS can't help you? Help!

Looking at other posts about this problem and my earlier post several years ago, it seems that I created a build phase that created the _MASReceipt folder in the target. This is now gone. I didn't do this so it looks like a bug in XCode. How can I recreate it? This is not likely to solve the problem because the dataWithContentsOfURL crashing the App is certainly a bug. The other thread about this is six months old and there is no solution to this problem.