Attempting to upgrade to Xcode 16 from 15.3. My team is installing the application from the Apple Developer website, and we are able to successfully install the application and run it. The issue occurs when attempting to install the iOS 18 simulator. We continue to get the same error when attempting to install the simulator via: Xcode CLI using the xcodebuild -downloadPlatform iOS command Downloading the dmg file from the Apple Developer website and running xcrun simctl runtime add iOS_18_Simulator_Runtime.dmg The error we continue to get is the following: Downloading iOS 18.0 Simulator (22A3351): Error: Error Domain=DVTDownloadableErrorDomain Code=29 "Registering simulator runtime with CoreSimulator failed." UserInfo={NSLocalizedDescription=Registering simulator runtime with CoreSimulator failed., NSUnderlyingError=0x600002c70930 {Error Domain=com.apple.CoreSimulator.simdiskimaged.SimDiskImageError Code=10 "Mount failed: SUIS premount dissented" UserInfo={NSLocalizedDescription=Mount failed: SUIS premount dissented, NSLocalizedFailureReason=the operation is not appropriate (kDAReturnNotPermitted)}}} We have attempted reinstalling Xcode multiple times, including cleaning out the Developer directory. We made sure there is over 50GB of space available on the disk, to validate it isn't a space issue. We're currently on macOS Sonoma 14.6.1, which looks like it should be compatible, and might look at updating to macOS 15 to see if that corrects the issue.