Hey everyone,
Just wanted to share a critical issue we’ve encountered while testing our app on iOS 18 simulators and devices using Xcode 26 Beta 3:
Crash Details
We're seeing the following fatal exception during launch:
NSInvalidUnarchiveOperationException
Could not instantiate class named _TtGC5UIKit17UICoreHostingViewVCS_21ToolbarVisualProvider8RootView_ because no class named _TtGC5UIKit17UICoreHostingViewVCS_21ToolbarVisualProvider8RootView_ was found...
The crash originates from Storyboards/XIBs that include a UIToolbar. It appears UIKit is referencing an internal SwiftUI-related class (UICoreHostingView), which isn't present at runtime — leading to immediate crashes.
Affected:
- Apps using UIToolbar in Storyboards or XIBs
- Running on iOS 18 (Simulators or Devices) and below
- Built using Xcode 26 Beta 3
CrashLog:
Fatal Exception: NSInvalidUnarchiveOperationException
0 CoreFoundation 0x11a21c __exceptionPreprocess
1 libobjc.A.dylib 0x31abc objc_exception_throw
2 CoreFoundation 0x178ea0 -[NSException initWithCoder:]
3 UIFoundation 0x28774 UINibDecoderDecodeObjectForValue
4 UIFoundation 0x28a18 UINibDecoderDecodeObjectForValue
5 UIFoundation 0x28cac -[UINibDecoder decodeObjectForKey:]
6 UIKitCore 0x21e680 -[UIView initWithCoder:]
7 UIKitCore 0x9b4784 -[UIToolbar initWithCoder:]
8 UIFoundation 0x28890 UINibDecoderDecodeObjectForValue
9 UIFoundation 0x28cac -[UINibDecoder decodeObjectForKey:]
10 UIKitCore 0x1e3a80 -[UIRuntimeConnection initWithCoder:]
11 UIFoundation 0x28890 UINibDecoderDecodeObjectForValue
12 UIFoundation 0x28a18 UINibDecoderDecodeObjectForValue
13 UIFoundation 0x28cac -[UINibDecoder decodeObjectForKey:]
14 UIKitCore 0x1e87dc -[NSCoder(UIIBDependencyInjectionInternal) _decodeObjectsWithSourceSegueTemplate:creator:sender:forKey:]
15 UIKitCore 0x1e2ea4 -[UINib instantiateWithOwner:options:]
16 UIKitCore 0x9f96c -[UIViewController loadView]
17 UIKitCore 0x75da8 -[UIViewController loadViewIfRequired]
18 UIKitCore 0x14430 -[UIViewController view]
19 UIKitCore 0x4237bc -[UINavigationController _preferredContentSizeForcingLoad:]
20 UIKitCore 0x116b15c -[_UISheetPresentationMetrics formSheetSizeForViewController:windowSize:screenSize:]
21 UIKitCore 0xb5c60c -[UIViewController _formSheetSizeForWindowWithSize:screenSize:]
22 UIKitCore 0x546ebc -[_UISheetLayoutInfo _preferredSize]
23 UIKitCore 0x18da60 -[_UISheetLayoutInfo _isEdgeAttached]
24 UIKitCore 0x19d428 -[_UISheetLayoutInfo _margins]
25 UIKitCore 0x19ce88 -[_UISheetLayoutInfo _stackAlignmentFrame]
26 UIKitCore 0x211018 -[_UISheetLayoutInfo _fullHeightUntransformedFrame]
27 UIKitCore 0x18f39c -[_UISheetLayoutInfo _untransformedFrame]
28 UIKitCore 0x188350 -[UISheetPresentationController _containerViewLayoutSubviews]
29 UIKitCore 0x18f1fc -[UITransitionView layoutSubviews]
30 UIKitCore 0x26070 -[UIView(CALayerDelegate) layoutSublayersOfLayer:]
31 QuartzCore 0x14c14 CA::Layer::layout_if_needed(CA::Transaction*)
32 UIKitCore 0x16b78 -[UIView(Hierarchy) layoutBelowIfNeeded]
33 UIKitCore 0x186f4c -[UISheetPresentationController presentationTransitionWillBegin]
34 UIKitCore 0x3187b4 -[_UIFormSheetPresentationController presentationTransitionWillBegin]
35 UIKitCore 0x185dd0 __80-[UIPresentationController _initViewHierarchyForPresentationSuperview:inWindow:]_block_invoke
36 UIKitCore 0x1874f8 __77-[UIPresentationController runTransitionForCurrentStateAnimated:handoffData:]_block_invoke_3
37 UIKitCore 0x8584c -[_UIAfterCACommitBlock run]
38 UIKitCore 0x85784 -[_UIAfterCACommitQueue flush]
39 UIKitCore 0xa254 _runAfterCACommitDeferredBlocks
40 UIKitCore 0x9f74 _cleanUpAfterCAFlushAndRunDeferredBlocks
41 UIKitCore 0x9e84 _UIApplicationFlushCATransaction
42 UIKitCore 0x9e0c __setupUpdateSequence_block_invoke_2
43 UIKitCore 0x9404 _UIUpdateSequenceRun
44 UIKitCore 0x8ab4 schedulerStepScheduledMainSection
45 UIKitCore 0x41e4 runloopSourceCallback
46 CoreFoundation 0xfa8c __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__
47 CoreFoundation 0xf8a4 __CFRunLoopDoSource0
48 CoreFoundation 0xf700 __CFRunLoopDoSources0
49 CoreFoundation 0x10080 __CFRunLoopRun
50 CoreFoundation 0x11c3c CFRunLoopRunSpecific
51 GraphicsServices 0x1454 GSEventRunModal
52 UIKitCore 0x135274 -[UIApplication _run]
53 UIKitCore 0x100a28 UIApplicationMain
54 Saleslink DEV 0x1f9ea8 main + 17 (AppDelegate.swift:17)
55 ??? 0x1af61bf08 (Missing)
Would love to know if anyone else has encountered this, or if there’s an official radar or feedback ID we can follow. Hoping this gets resolved before the GM release of Xcode 26.
Thanks!
Here's another thread with other folks who are affected by the same issue. As you mention this is critical to you, make sure you file your own bug report for this, and please post the FB number of that report here.
— Ed Ford, DTS Engineer
