UIKit crash on app built with Xcode 26 but run on iOS 18.X

Question

Created Jul ’25

Replies 13

Boosts 3

Participants 8

An app built on Xcode 26 (beta4) presents various UIViewCOntrollers. Presentation of any UIViewController that contains a UIToolbar leads to a UIKit crash when run on an iOS 18.5 device, it does not crash when run on iOS 26.

The exception logged:

*** Terminating app due to uncaught exception 'NSInvalidUnarchiveOperationException', reason: 'Could not instantiate class named TtGC5UIKit17UICoreHostingViewVCS_21ToolbarVisualProvider8RootView because no class named TtGC5UIKit17UICoreHostingViewVCS_21ToolbarVisualProvider8RootView was found; the class needs to be defined in source code or linked in from a library (ensure the class is part of the correct target)'

Anyone else seen this?

I've submitted a bug report via Feedback Assistant, including a minimal Xcode workspace that reproduces the crash, hoping this will get some attention.

Boost

Answer 1

DTS Engineer OP

Apple

Jul ’25

I've submitted a bug report via Feedback Assistant, including a minimal Xcode workspace that reproduces the crash

That's the right thing to do, thank you! Could you share the FB number of your report?

— Ed Ford,  DTS Engineer

0

Answer 2

Vertifi OP

Jul ’25

Thanks Ed, its FB18995026

1

Answer 3

lifjoy OP

Jul ’25

Also experiencing the same issue. Submitted FB18845125.

1

Answer 4

KT_ OP

Jul ’25

Hi Ed, sorry about the wrong feedback. Ran into the problem again just now and submitted FB19209098. Happened in simulator and on device.

1

Answer 5

joecrabtree OP

Jul ’25

Same here. I filed 2 feedbacks as I wasn't sure whether to file against Xcode or the SDK.
I included a simple test project.

Feedback numbers are: FB19254965 FB19254927

1

Answer 6

KT_ OP

Jul ’25

Clearly I'm mixing up my FBs and going crosseyed. this one is actually this crash. FB19270537

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Answer 7

KarlPark OP

Aug ’25

Same here. Submitted FB19343306

1

Answer 8

Vertifi OP

4w

This is not corrected in Xcode 26 beta 5

1

Answer 9

hsingh-texada OP

4w

Facing the same issue: FB19085434.

Separate thread with more crash logs.

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Answer 10

hsingh-texada OP

4w

The other issue that I talked about in my previous comment: https://developer.apple.com/forums/thread/794669

1

Answer 11

Jason Cox OP

3w

We’re seeing this issue as well when building against iOS 26 Beta 4 and Beta 5 SDK’s targeting iOS 18.6.

FB19549624

1

Answer 12

Vertifi OP

2w

This is corrected on Xcode 26 beta 6 / iOS 26 beta 7, marking FB18995026 closed, thanks!

0

Answer 13

KT_ OP

2w

I think this got fixed on the Xcode beta released today (6, but device version is beta 7). I say I think because it worked on my side, both 18.2 and 18.5. Very much appreciate everyone's time who addressed this.

1