# Mac File Chooser assertion

**URL:** <https://forum.juce.com/t/mac-file-chooser-assertion/13899>\
**Category:** MacOSX and iOS\
**Created:** [November 18, 2014, 11:01pm UTC](https://forum.juce.com/t/mac-file-chooser-assertion/13899 "2014-11-18T23:01:07Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![onereddog](https://avatars.discourse-cdn.com/v4/letter/o/dbc845/32.png) [@onereddog](https://forum.juce.com/u/onereddog)\
**Post date:** [November 18, 2014, 11:01pm UTC](https://forum.juce.com/t/mac-file-chooser-assertion/13899/1 "2014-11-18T23:01:07Z")

</div>

Hi,&nbsp;

I'm seeing a failure in the FileChooser under OS X 10.10.1 with Xcode 6.1 and JUCE 3.1 (it was also happening yesterday pre the 3.1 commits).

Showing the FileChooser like this:

```
FileChooser myChooser("Please choose a valid Hull preset.", File::getSpecialLocation(File::userHomeDirectory), "*.hullsynthpreset");

if (myChooser.browseForFileToOpen())
{
    File selectedFile = myChooser.getResult();
    XmlDocument myDocument(selectedFile.loadFileAsString());
    XmlElement* mainElement = myDocument.getDocumentElement();
    if (mainElement != NULL)
    {
        filter->setStateInformationFromXml(mainElement);
    }
}
```

I get the following crash - which looks like something is modifying an NSMutableArray while it's being enumerated.

```
2014-11-19 09:50:52.645 Hull[24361:2307407] *** Collection <__NSArrayM: 0x25cdbafd0> was mutated while being enumerated.
2014-11-19 09:50:52.653 Hull[24361:2307407] (
    0 CoreFoundation 0x00007fff9c06864c __exceptionPreprocess + 172
    1 libobjc.A.dylib 0x00007fff924e36de objc_exception_throw + 43
    2 CoreFoundation 0x00007fff9c067ee5 __NSFastEnumerationMutationHandler + 309
    3 AppKit 0x00007fff93743c24 -[NSView _recursiveSendViewDidChangeAppearance:] + 193
    4 AppKit 0x00007fff93743c3b -[NSView _recursiveSendViewDidChangeAppearance:] + 216
    5 AppKit 0x00007fff93743c3b -[NSView _recursiveSendViewDidChangeAppearance:] + 216
    6 AppKit 0x00007fff93743c3b -[NSView _recursiveSendViewDidChangeAppearance:] + 216
    7 AppKit 0x00007fff93743c3b -[NSView _recursiveSendViewDidChangeAppearance:] + 216
    8 AppKit 0x00007fff93743c3b -[NSView _recursiveSendViewDidChangeAppearance:] + 216
    9 AppKit 0x00007fff93743c3b -[NSView _recursiveSendViewDidChangeAppearance:] + 216
    10 AppKit 0x00007fff93743c3b -[NSView _recursiveSendViewDidChangeAppearance:] + 216
    11 AppKit 0x00007fff93743c3b -[NSView _recursiveSendViewDidChangeAppearance:] + 216
    12 AppKit 0x00007fff93743c3b -[NSView _recursiveSendViewDidChangeAppearance:] + 216
    13 AppKit 0x00007fff93743c3b -[NSView _recursiveSendViewDidChangeAppearance:] + 216
    14 AppKit 0x00007fff93743c3b -[NSView _recursiveSendViewDidChangeAppearance:] + 216
    15 AppKit 0x00007fff93743c3b -[NSView _recursiveSendViewDidChangeAppearance:] + 216
    16 AppKit 0x00007fff93743c3b -[NSView _recursiveSendViewDidChangeAppearance:] + 216
    17 AppKit 0x00007fff93743c3b -[NSView _recursiveSendViewDidChangeAppearance:] + 216
    18 AppKit 0x00007fff93743c3b -[NSView _recursiveSendViewDidChangeAppearance:] + 216
    19 AppKit 0x00007fff93743941 -[NSView setAppearance:] + 205
    20 AppKit 0x00007fff93d4605c -[NSThemeFrame setAppearance:] + 52
    21 AppKit 0x00007fff936c23ca -[NSWindow setAppearance:] + 44
    22 AppKit 0x00007fff93c25f93 +[NSSavePanel _crunchyRawUnbonedPanel] + 298
    23 Hull 0x00000001003caa03 _ZN4juce11FileChooser18showPlatformDialogERNS_5ArrayINS_4FileENS_20DummyCriticalSectionELi0EEERKNS_6StringERKS2_S8_bbbbbPNS_20FilePreviewComponentE + 899
    24 Hull 0x00000001003ca1af _ZN4juce11FileChooser10showDialogEiPNS_20FilePreviewComponentE + 751
    25 Hull 0x00000001003c9eb4 _ZN4juce11FileChooser19browseForFileToOpenEPNS_20FilePreviewComponentE + 36
    26 Hull 0x000000010005a07f _ZN24HullAudioProcessorEditor13buttonClickedEPN4juce6ButtonE + 1951
    27 Hull 0x000000010005a35f _ZThn224_N24HullAudioProcessorEditor13buttonClickedEPN4juce6ButtonE + 47
    28 Hull 0x000000010045ac06 _ZN4juce12ListenerListINS_6Button8ListenerENS_5ArrayIPS2_NS_20DummyCriticalSectionELi0EEEE11callCheckedINS_9Component14BailOutCheckerEPS1_EEvRKT_MS2_FvT0_ENS_11TypeHelpers13ParameterTypeISF_E4typeE + 214
    29 Hull 0x00000001003a7344 _ZN4juce6Button16sendClickMessageERKNS_12ModifierKeysE + 308
    30 Hull 0x00000001003a6f46 _ZN4juce6Button14setToggleStateEbNS_16NotificationTypeE + 470
    31 Hull 0x00000001003a79a0 _ZN4juce6Button21internalClickCallbackERKNS_12ModifierKeysE + 144
    32 Hull 0x00000001003a7f9b _ZN4juce6Button7mouseUpERKNS_10MouseEventE + 155
    33 Hull 0x000000010039b8b9 _ZN4juce9Component15internalMouseUpENS_16MouseInputSourceENS_5PointIfEENS_4TimeENS_12ModifierKeysE + 585
    34 Hull 0x00000001004c6276 _ZN4juce24MouseInputSourceInternal11sendMouseUpERNS_9ComponentENS_5PointIfEENS_4TimeENS_12ModifierKeysE + 198
    35 Hull 0x00000001004c5ce3 _ZN4juce24MouseInputSourceInternal10setButtonsENS_5PointIfEENS_4TimeENS_12ModifierKeysE + 755
    36 Hull 0x0000000100457c07 _ZN4juce24MouseInputSourceInternal11handleEventERNS_13ComponentPeerENS_5PointIfEENS_4TimeENS_12ModifierKeysE + 583
    37 Hull 0x000000010039e69f _ZN4juce16MouseInputSource11handleEventERNS_13ComponentPeerENS_5PointIfEExNS_12ModifierKeysE + 127
    38 Hull 0x0000000100442ef9 _ZN4juce13ComponentPeer16handleMouseEventEiNS_5PointIfEENS_12ModifierKeysEx + 185
    39 Hull 0x00000001004cc343 _ZN4juce19NSViewComponentPeer14sendMouseEventEP7NSEvent + 115
    40 Hull 0x00000001004cc8b9 _ZN4juce19NSViewComponentPeer15redirectMouseUpEP7NSEvent + 105
    41 Hull 0x00000001004c92ec _ZN4juce15JuceNSViewClass12asyncMouseUpEP11objc_objectP13objc_selectorP7NSEvent + 60
    42 Hull 0x00000001004c9277 _ZN4juce15JuceNSViewClass7mouseUpEP11objc_objectP13objc_selectorP7NSEvent + 55
    43 AppKit 0x00007fff93dab02b -[NSWindow _reallySendEvent:] + 759
    44 AppKit 0x00007fff9383850c -[NSWindow sendEvent:] + 368
    45 AppKit 0x00007fff937ea096 -[NSApplication sendEvent:] + 2238
    46 AppKit 0x00007fff93676e98 -[NSApplication run] + 711
    47 Hull 0x0000000100277450 _ZN4juce14MessageManager15runDispatchLoopEv + 144
    48 Hull 0x000000010027733f _ZN4juce19JUCEApplicationBase4mainEv + 415
    49 Hull 0x000000010027713c _ZN4juce19JUCEApplicationBase4mainEiPPKc + 60
    50 Hull 0x0000000100062363 main + 51
    51 Hull 0x0000000100001db4 start + 52
    52 ??? 0x0000000000000003 0x0 + 3
)

​
```

I did some debugging and it's causing an exception breakpoint in juce\_mac\_FileChooser.m line 139 when it invokes [NSOpenPanel openPanel].&nbsp;

Has anyone else seen this, is it an OS X Cocoa bug?&nbsp;I know I'm kinda on the bleeding edge with my OS X verison.

regards

peter

&nbsp;