UIWebView crashes and i have no idea why

Question

Im having trouble trying to figure this problem out because no matter what I do to get my problem to work i keep getting this crash

Heres the trace

 $0 = 0x1f8f9a10 (

    0   ???                                 0x02b04144 0x0 + 45105476,
    1   TheAppName                          0x001016e0 start + 0,
    2   Foundation                          0x34334599  + 72,
    3   WebCore                             0x399e7bfb  + 82,
    4   UIKit                               0x3595b493  + 182,
    5   UIKit                               0x358d7d1f  + 382,
    6   UIKit                               0x358d7d33  + 402,
    7   UIKit                               0x358d7d33  + 402,
    8   UIKit                               0x358d7431  + 360,
    9   UIKit                               0x358d72c3  + 30,
    10  UIKit                               0x35ce2fef  + 386,
    11  UIKit                               0x35ce3879  + 464,
    12  UIKit                               0x35ce63d3  + 698,
    13  UIKit                               0x35ce5e49  + 552,
    14  UIKit                               0x35ce28dd  + 172,
    15  UIKit                               0x358d8803  + 258,
    16  QuartzCore                          0x35682d8b  + 214,
    17  QuartzCore                          0x35682929  + 460,
    18  QuartzCore                          0x3568385d  + 16,
    19  QuartzCore                          0x35683243  + 238,
    20  QuartzCore                          0x35683051  + 316,
    21  QuartzCore                          0x356ba0f7  + 254,
    22  QuartzCore                          0x356b9ff1  + 64,
    23  IOMobileFramebuffer                 0x37915fd7  + 154,
    24  IOKit                               0x346b4449 IODispatchCalloutFromCFMessage + 192,
    25  CoreFoundation                      0x33a975db  + 118,
    26  CoreFoundation                      0x33aa2173  + 34,
    27  CoreFoundation                      0x33aa2117  + 138,
    28  CoreFoundation                      0x33aa0f99  + 1384,
    29  CoreFoundation                      0x33a13ebd CFRunLoopRunSpecific + 356,
    30  CoreFoundation                      0x33a13d49 CFRunLoopRunInMode + 104,
    31  GraphicsServices                    0x375ca2eb GSEventRunModal + 74,
    32  UIKit                               0x35929301 UIApplicationMain + 1120,
    33  TheAppName                          0x001332d9 main + 116,
    34  TheAppName                          0x00101708 start + 40
    )

What i am doing is using a UIPageViewController as a slideshow. Sometimes when the page turns I need to load up an HTML file with a web view, these html files contain html code used to animate objects in the html page. So everytime I crete a new view controller to display in the pageViewController I need to destroy the webview because the aniamtion wont animate when going from one animation to another. Sometimes it works but sometimes it causes this crash. Now i have no idea how to read up on this since webviews are not documented so detailed as this message is. So does anyone know exactly what is going on here??

Code spit out when it breaks

    WebCore`WebCore::Page::setDeviceScaleFactor(float):
    0x399edbc0:  push   {r4, r5, r7, lr}
    0x399edbc2:  mov    r4, r0
    0x399edbc4:  vmov   d0, r1, r1
    0x399edbc8:  vldr   s2, [r4, #100]
    0x399edbcc:  add    r7, sp, #8
    0x399edbce:  vcmpe.f32s2, s0
    0x399edbd2:  vmrs   APSR_nzcv, fpscr
    0x399edbd6:  it     eq
    0x399edbd8:  popeq  {r4, r5, r7, pc}
    0x399edbda:  vstr   s0, [r4, #100]
    0x399edbde:  ldr    r5, [r4, #56]
    0x399edbe0:  cbz    r5, 0x399edc22            ; WebCore::Page::setDeviceScaleFactor(float) + 98
    0x399edbe2:  ldr.w  r0, [r5, #804]
    0x399edbe6:  movs   r1, #1
    0x399edbe8:  bl     0x39a3c3c0                ; WebCore::Document::styleResolverChanged(WebCore::StyleResolverUpdateFlag)
    0x399edbec:  add.w  r0, r5, #28
    0x399edbf0:  movs   r1, #0
    0x399edbf2:  bl     0x399f9ed0                ; WebCore::FrameTree::traverseNext(WebCore::Frame const*) const
    0x399edbf6:  mov    r5, r0
    0x399edbf8:  cmp    r5, #0
    0x399edbfa:  bne    0x399edbe2                ; WebCore::Page::setDeviceScaleFactor(float) + 34
    0x399edbfc:  ldr    r0, [r4, #56]
    0x399edbfe:  cmp    r0, #0
    0x399edc00:  beq    0x399edc22                ; WebCore::Page::setDeviceScaleFactor(float) + 98
    0x399edc02:  bl     0x39dee4f4                ; WebCore::Frame::deviceOrPageScaleFactorChanged()
    0x399edc06:  ldr    r5, [r4, #56]
    0x399edc08:  b      0x399edc1e                ; WebCore::Page::setDeviceScaleFactor(float) + 94
    0x399edc0a:  add.w  r0, r5, #872
    0x399edc0e:  bl     0x39dc7fa0                ; WebCore::Editor::deviceScaleFactorChanged()
    0x399edc12:  add.w  r0, r5, #28
    0x399edc16:  movs   r1, #0
    0x399edc18:  bl     0x399f9ed0                ; WebCore::FrameTree::traverseNext(WebCore::Frame const*) const
    0x399edc1c:  mov    r5, r0
    0x399edc1e:  cmp    r5, #0
    0x399edc20:  bne    0x399edc0a                ; WebCore::Page::setDeviceScaleFactor(float) + 74
    0x399edc22:  bl     0x399e6ed8                ; WebCore::pageCache()
    0x399edc26:  mov    r1, r4
    0x399edc28:  pop.w  {r4, r5, r7, lr}
    0x399edc2c:  b.w    0x399edc30                ; WebCore::PageCache::markPagesForFullStyleRecalc(WebCore::Page*)

Answer 1

You may stop webview loading on your viewWillDisappear method

[webview stopLoading]
webview.delegate = nil;

or with an additional set it to blank page

[webview loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:@"about:blank"]]];

good luck!

Answer 2

Not sure if this will fix your issue, but try setting the delegate of the webview to nil when you destroy the webview. If you get a UIWebViewDelegate callback after the webview has been dealloced, your app will crash.