XCPreviewAgent crashes with KERN_PROTECTION_FAILURE on macOS 26.0.1 Tahoe

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den2207 OP

Created 1d

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Hello, I'm experiencing consistent crashes of XCPreviewAgent when using Xcode Previews on macOS 26.0.1 Tahoe (25A362).

Configuration:

macOS: 26.0.1 (25A362) - stable release
Xcode: 16.0 (23.0.54) - stable release
Hardware: MacBook Pro M4
Project: SwiftUI iOS app

Issue: Every time I try to use Xcode Previews, XCPreviewAgent crashes with: Exception Type: EXC_BAD_ACCESS (SIGBUS) Exception Subtype: KERN_PROTECTION_FAILURE at 0x0000000340e54000 Termination Reason: Namespace SIGNAL, Code 10, Bus error: 10 The crash occurs in shared memory region during dynamic library loading. What I've tried:

Cleared all caches: rm -rf ~/Library/Developer/Xcode/DerivedData
Deleted Preview data: rm -rf ~/Library/Developer/Xcode/UserData/Previews
Reset simulators: xcrun simctl --set previews delete all
Switched xcode-select to /Applications/Xcode.app/Contents/Developer
Tried both Xcode stable and Xcode beta
Created fresh simulators
Clean build (Cmd+Shift+K)
Rebooted Mac multiple times

The app runs fine on simulator (Cmd+R), but Previews consistently crash.

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Answer 1

Developer Tools Engineer OP

Apple

22h

Hi,

Sorry to hear you are having problems getting previews working. If you look into the folder ~/Library/Logs/DiagnosticReports, do you see any crash reports for XCPreviewAgent? If so, would you be able to attach them here?

If not, the best next step will be to file a feedback with diagnostics so we can take a look.

We will need the diagnostics Xcode Previews generates in order to make sure we understand the error the previews system is encountering.

Install the logging profile using instructions available here: https://developer.apple.com/bug-reporting/profiles-and-logs/?name=swift On your mac running Xcode, and on your physical preview device (if you are using one).

Install the logging profile using the following instructions on your mac running Xcode; and if you are using one, your physical preview device (iOS or visionOS): https://developer.apple.com/bug-reporting/profiles-and-logs/?name=swift

Then when you reproduce the problem in Xcode:

Either (a) an error banner will appear, click the "Diagnostics" button in that banner; or (b) if you're not seeing an error but you still want to provide diagnostics you can get the same diagnostics window by going under the Editor menu in the menu bar, then selecting the Canvas submenu, then selecting "Diagnostics".
In the sheet that appears, click "Generate Report" in the bottom left of the sheet
Attach (or make from the folder) the resulting zip file to the bug (will be named something like previews-diagnostics-0123456789.zip)
Generate a sysdiagnose on your mac and any on-device preview devices, and attach those too

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