Q:

Crash on MFMailComposeViewController

if ([MFMailComposeViewController canSendMail]) {

    MFMailComposeViewController *mailViewController = [[MFMailComposeViewController alloc] init];
    mailViewController.mailComposeDelegate = self;
    [mailViewController setSubject:@"Support Enquiry"];
    [mailViewController setToRecipients:[NSArray arrayWithObject:EMAIL_SUPPORT]];

    [self presentModalViewController:mailViewController animated:YES];
    [mailViewController release];
}

My code crashes on the 
MFMailComposeViewController *mailViewController = [[MFMailComposeViewController alloc] init]; 

line with: 
*** Terminating app due to uncaught exception 'CALayerInvalidGeometry', 
reason: 'CALayer position contains NaN: [nan 24.5]'
*** Call stack at first throw:
(
0   CoreFoundation                      0x011f75a9 __exceptionPreprocess + 185
1   libobjc.A.dylib                     0x0134b313 objc_exception_throw + 44
2   CoreFoundation                      0x011afef8 +[NSException raise:format:arguments:] + 136
3   CoreFoundation                      0x011afe6a +[NSException raise:format:] + 58
4   QuartzCore                          0x00145ba2 _ZL18CALayerSetPositionP7CALayerRKN2CA4Vec2IdEEb + 177
5   QuartzCore                          0x00145d55 -[CALayer setPosition:] + 42
6   QuartzCore                          0x0013e24d -[CALayer setFrame:] + 763
7   UIKit                               0x0047eda2 -[UIView(Geometry) setFrame:] + 255
8   UIKit                               0x004ea660 -[UITextField setFrame:] + 166
9   MessageUI                           0x001faa48 -[_MFComposeRecipientView reflow] + 3371
10  MessageUI                           0x001f9678 -[_MFComposeRecipientView setLabel:] + 79
11  MessageUI                           0x001ff144 -[MFMailComposeView _setupField:withLabel:navTitle:property:changingView:toSize:fieldFrame:visible:] + 234
12  MessageUI                           0x00203277 -[MFMailComposeView _layoutSubviews:changingView:toSize:searchResultsWereDismissed:] + 1768
13  MessageUI                           0x001fea6f -[MFMailComposeView _layoutSubviews:changingView:toSize:] + 71
14  MessageUI                           0x001fea22 -[MFMailComposeView _layoutSubviews:] + 69
15  MessageUI                           0x00200859 -[MFMailComposeView initWithFrame:navigationItem:options:delegate:] + 2175
16  MessageUI                           0x00215ea6 -[MFMailComposeController initializeUI] + 228
17  MessageUI                           0x0021cfb9 -[MFMailComposeController initForContentSize:navigationItem:options:] + 147
18  MessageUI                           0x00236267 -[MFMailComposeRootViewController initWithCompositionContext:contentSize:mailComposeControllerOptions:] + 377
19  MessageUI                           0x0022fbe7 -[MFMailComposeViewController initWithComposition:contentSize:mailComposeControllerOptions:] + 726
20  MessageUI                           0x0022f634 -[MFMailComposeViewController initWithComposition:] + 68
21  MessageUI                           0x0022f71e -[MFMailComposeViewController initWithNibName:bundle:] + 98

...
Any idea whats going on?
EDIT: All the answer so far have done nothing, it still crashes :(
EDIT 2: I finally figured out the problem - I had added a category to text field and MFMailComposeViewController did not like that at all.

A:

As the asker reported on his question, MFMailComposeViewController uses some native elements that shouldn't be categorized. So, you have to be sure there aren't any categories on elements like UITextField or UITextView.

