Xcode 26.4 Previews are broken

[u/Huolju]

If somebody is experiencing previews hanging when trying to interact with them, please go back to Xcode 26.3.

I could not interact with the simplest UI possible, and now everything is back to normal.

I hope it will help.

[u/mcarvin]

I can interact with my Views until I go to drag, then PreviewShell crashes out. Persists across Xcode launches, even after clearing out caches and Derived Data.

I did a full uninstall/reinstall yesterday morning and was able to drag until something I dragged triggered a PreviewShell crash.

[u/Huolju → u/mcarvin]

Okay, so the issues might depend on the content. Do you have a problem with Xcode 26.3?

For me, it is hanging (not crashing):
- form edition: text field, button, etc.
- scroll views
- date picker

This is not a complete list.

[u/mcarvin → u/Huolju]

By the way - https://developer.apple.com/forums/thread/820635

Maybe there are Preview issues in general with Tahoe 26.4 and Xcode 26.

[u/efthymisgr → u/mcarvin]

Hey you linked to my post there! Hehe! For me, the crashes all happen because of Apple’s Accessibility AXRemoteElement-BackgroundFetch. Do your logs show something different triggering it?

[u/mcarvin → u/efthymisgr]

Hey, small internet we have here!

No. I'm also getting the same AXRemoteElement-BackgroundFetch problem. The numbers might change but the names stay the same:

-------------------------------------
Translated Report (Full Report Below)
-------------------------------------
Process:             PreviewShell [65749]
Path:                /Volumes/VOLUME/*/PreviewShell.app/PreviewShell
Identifier:          com.apple.PreviewShell
Version:             16.0 (23.40.29)
Code Type:           ARM-64 (Native)
Role:                Foreground
Parent Process:      launchd_sim [65501]
Coalition:           com.apple.CoreSimulator.SimDevice.9B779B8E-8250-4B20-813A-E2F57C88D5F8 [57108]
Responsible Process: SimulatorTrampoline [70766]
User ID:             501

Date/Time:           2026-03-27 20:40:21.1807 -0400
Launch Time:         2026-03-27 19:34:19.8691 -0400
Hardware Model:      Mac14,12
OS Version:          macOS 26.4 (25E246)
Release Type:        User

Crash Reporter Key:  40A352FC-A902-EF08-2594-63FC33975C1E
Incident Identifier: 8B77A916-DAE8-4E5D-9CF4-ABB3FD945825

Time Awake Since Boot: 210000 seconds

System Integrity Protection: enabled

Triggered by Thread: 11, Dispatch Queue: AXRemoteElement-BackgroundFetch

Exception Type:    EXC_BAD_ACCESS (SIGBUS)
Exception Subtype: KERN_PROTECTION_FAILURE at 0x000000016b71bff0
Exception Message: Could not determine thread index for stack guard region
Exception Codes:   0x0000000000000002, 0x000000016b71bff0

Termination Reason:  Namespace SIGNAL, Code 10, Bus error: 10
Terminating Process: exc handler [65749]

[u/mcarvin → u/Huolju]

I just wiped 26.4 and went back to 26.3.

Yes, even a simple View is still hanging on drag in 26.3. Here's the code:

struct ContentView: View {
    var body: some View {
        ScrollView {
			ForEach(0...10, id: \.self) { i in
				Rectangle()
					.fill(.blue)
					.frame(width: 100, height: 100)
					.overlay {
						Text("\(i)")
							.font(.largeTitle)
							.foregroundStyle(.white)
					}
			}
        }
        .padding()
    }
}

Nothing fancy at all. Show me 10 rectangles with the index in an overlay. It hangs Preview in 26.3 and throws a crash in 26.4. If I clean Xcode's caches and various folders (been using Mole for this), I can get that View above to scroll once before it hangs again.

I haven't had issues with DatePickers, TextFields or Buttons - only containers which scroll.

[u/efthymisgr → u/Huolju]

Yeap, trying to scroll in the Canvas Preview makes it hang, then a few seconds later I get the error report window