I experienced this problem in XCode 26.0.1. My app has a single target configured with iOS and macOS destinations. For macOS, my app requires the sandbox entitlement for calendar data access. I fixed the error by: Removing the com.apple.application-identifier, com.apple.security.app-sandbox, and com.apple.security.personal-information.calendars entries from the app's AppName.entitlements file. Adding the sandbox and calendar entitlements back by adding the corresponding capabilities in the app target Signing & Capabilities settings. Toggling off and back on "Automatically manage signing". I believe this worked because sandbox capability entitlements are only injected for macOS, while entitlement file entitlements were injected for all destinations. Hopefully this helps others with similar dual-destination setups.