title: IOS App crashes when attachement file is opened while uithread is busy
body: <p>I have an app in which I have to do a lot of activity in <code>UIThread</code>. When <code>UIThread</code> is blocked and if I try to open an email attachment in my app, it crashes. I cannot get any crash log. The app quits. If I try to open when app is not busy then there is no problem. How can I solve this issue?</p>