Xcode 26 SDK/Simulator Download Issue: (-67061 invalid signature (code or signature have been modified)

Hello there!

I’m currently stuck with Xcode 26.0 beta 6 (17A5305f), as I can’t download the latest SDK/Simulator for iOS 26.0 beta 6 (23A5324a). The download constantly fails for days now with the following error message:

(-67061 invalid signature (code or signature have been modified)
Domain: SimDiskImageErrorDomain
Code: 5
User Info: {
    DVTErrorCreationDateKey = "2025-08-26 21:11:30 +0000";
    unusableErrorDetail = "";
}
--
(-67061 invalid signature (code or signature have been modified)
Domain: SimDiskImageErrorDomain
Code: 5
User Info: {
    unusableErrorDetail = "";
}
--


System Information

macOS Version 15.6.1 (Build 24G90)
Xcode 26.0 (24208.7) (Build 17A5305f)
Timestamp: 2025-08-26T23:11:30+02:00

I’ve already tried re-downloading the Xcode beta 6 from the Apple Developer site. I’ve also tried restarting my Mac and even tried to use the command line to install iOS 26 beta SDK via xcodebuild -downloadPlatform iOS -exportPath ~/Downloads (as noted here). This lead to the same error message.

Can someone help? I’m unable to develop my apps right now! 🫠

I’ve also filed a feedback: FB19915834