I tried to open a new sheet with:

[NSApp beginSheet:loeschenSheet modalForWindow:mainWindow modalDelegate:self didEndSelector:NULL contextInfo:nil];

It worked perfectly.

Then I tried to send an Action from another class to my sheetController, which should then open the sheet, but this is what I got:

2002-06-29 21:11:24.287 MyApp[6870] *** Assertion failure in -[NSApplication _commonBeginModalSessionForWindow:relativeToWindow:modalDelegate:didEndSelector:contextInfo:], NSApplication.m:2306 2002-06-29 21:11:24.299 MyApp[6870] Modal session requires modal window

Tried it with another action, and it worked, just not with this.

Hope this makes sense. g

– MartinWeil

Hmmm can you be a little more detailed? what action did, what action didnt?

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I am having the same issue, calling a sheet from a different class causes that. This is what I got:

DXTableViewController.m

#import “DXTableViewController.h” #import “DXApplicationController.h”

DXApplicationController* dxAppControl;

@implementation DXTableViewController

• (IBAction)addNewTask:(id)sender { dxAppControl = [[DXApplicationController alloc] init]; [dxAppControl beginSheetForTaksAddition]; }

DXApplicationController.m

#import “DXApplicationController.h” #import “DXTableViewController.h”

• (void)beginSheetForTaskAddition { [NSApp beginSheet:addSheet modalForWindow:[NSApp keyWindow] modalDelegate:NULL didEndSelector:NULL contextInfo:NULL]; }

I get the same error as our friend above:

2005-07-05 21:47:41.553 QuickTask[416] *** Assertion failure in -[NSApplication _commonBeginModalSessionForWindow:relativeToWindow:modalDelegate:didEndSelector:contextInfo:], AppKit.subproj/NSApplication.m:2763 2005-07-05 21:47:41.554 QuickTask[416] Modal session requires modal window

Any ideas? - FernandoLucasSantos

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Normally this error occurs because your sheet is nil. Check in the debugger to make sure that addSheet is actually a valid NSWindow.