UIKit has two places where it tries to present an action sheet on the rootViewController when it should present things on the topmost presentedViewController. This is our attempt of the least horrible workaround to fix this issue. (http://www.openradar.me/26295020).

PresentActionSheetWorkaround.mm

#warning This still misses safeguards and has private API references in it. Use only when you really know what you're doing!

// pspdf_swizzleSelectorWithBlock not provided. Use your swizzling helper of choice
// (e.g. http://petersteinberger.com/blog/2014/a-story-about-swizzling-the-right-way-and-touch-forwarding/)

// Fixes rdar://26295020
static void PSPDFInstallWorkaroundForSheetPresentationIssue26295020(void) {
    __block auto removeWorkaround = ^{};
    const auto installWorkaround = ^{
        const SEL presentSEL = @selector(presentViewController:animated:completion:);
        __block IMP origIMP = pspdf_swizzleSelectorWithBlock(UIViewController.class, presentSEL, ^(UIViewController *self, id vC, BOOL animated, id completion) {
            UIViewController *targetVC = self;
            while (targetVC.presentedViewController) {
                targetVC = targetVC.presentedViewController;
            }
            ((void (*)(id, SEL, id, BOOL, id))origIMP)(targetVC, presentSEL, vC, animated, completion);
        });
        removeWorkaround = ^{
            pspdf_swizzleSelector(UIViewController.class, presentSEL, origIMP);
        };
    };

    const SEL presentSheetSEL = NSSelectorFromString(@"presentSheetFromRect:");
    const auto swizzleOnClass = ^(Class klass) {
        const __block IMP origIMP = pspdf_swizzleSelectorWithBlock(klass, presentSheetSEL, ^(id self, CGRect rect) {
            // Before calling the original implementation, we swizzle the presentation logic on UIViewController
            installWorkaround();
            // UIKit later presents the sheet on [view.window rootViewController];
            // See https://github.com/WebKit/webkit/blob/1aceb9ed7a42d0a5ed11558c72bcd57068b642e7/Source/WebKit2/UIProcess/ios/WKActionSheet.mm#L102
            // Our workaround forwards this to the topmost presentedViewController instead.
            ((void (*)(id, SEL, CGRect))origIMP)(self, presentSheetSEL, rect);
            // Cleaning up again - this workaround would swallow bugs if we let it be there.
            removeWorkaround();
        });
    };
    swizzleOnClass(NSClassFromString(@"_UIRotatingAlertController"));
    swizzleOnClass(NSClassFromString(@"WKActionSheet"));
}

Is is affecting quite a few people:

• https://forums.developer.apple.com/message/61767#61767
• jessesquires/JSQMessagesViewController#1247
• https://stackoverflow.com/questions/32653268/error-on-textview-with-detection-phone-number-ios-9/37250578#37250578
• https://stackoverflow.com/questions/28379327/ios-warning-attempt-to-present-viewcontroller-whose-view-is-not-in-the-window
• https://stackoverflow.com/questions/27767785/long-press-leads-to-an-error-warning-when-wkwebview-tries-to-present-a-wkactions/37250479
• https://stackoverflow.com/questions/27767785/long-press-leads-to-an-error-warning-when-wkwebview-tries-to-present-a-wkactions/37250479

(...) has private API references in it.

Is it safe for your SDK customers?

Anyone have a Swift version here?

@tamastimar Yes, a variant of this solution ships in thousands of apps.
@MaximusMcCann: This is just trickier and uglier in Swift, simply use the ObjC variant, the languages mix very well and after all, you apply the patch to a pure ObjC(++) framework.