Unable to Download iOS 26 Simulator Runtime – “invalid signature (code or signature have been modified)” Error

When attempting to download the iOS 26 simulator runtime from Xcode → Settings → Platforms, the process fails with the following error:

(-67061 invalid signature (code or signature have been modified)
Domain: SimDiskImageErrorDomain
Code: 5
User Info: {
    unusableErrorDetail = "";
}

Even after manually importing other runtimes (e.g., iOS 18.2), they do not appear under Xcode → Product → Destination, and the simulator list remains empty.

System Information:

  • macOS: 26.0.1 (Build 25A362)
  • Xcode: 26.0.1 (24229) (Build 17A400)
  • Processor: Intel Core i5 (Intel-based Mac)

The error occurs consistently each time I try to download the runtime, preventing Xcode from adding the iOS 26 simulator. No third-party tools or manual modifications were made to Xcode. What I’ve Tried:

Restarted Xcode and macOS

  • Cleared DerivedData and simulator cache
  • Verified Xcode path via xcode-select -p
  • Imported iOS 18.2 runtime manually using:
xcodebuild -importPlatform "iOS_18.2_Simulator_Runtime.dm

Reset CoreSimulator service and re-created simulators via xcrun simctl

Despite all of this, no simulator appears in Xcode’s destination list, and I keep getting the signature validation error when trying to download iOS 26 from Xcode.

Unable to Download iOS 26 Simulator Runtime – “invalid signature (code or signature have been modified)” Error
 
 
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