I can add a sharper repro condition: this is specific to cloned simulators, not UI testing itself. Same XCUITest, same iOS 26.5 runtime, Xcode-managed parallel testing: Run serially on a normal simulator (-parallel-testing-enabled NO): the Files save sheet works, Save enables, test passes. Run with -parallel-testing-enabled YES (even with worker count 1, which still runs on a "Clone 1 of iPhone…" device): the save sheet opens, the filename is filled in, but the Save button is disabled from the first frame and never enables, and the document thumbnail never loads. Nothing app-side differs — the sheet is presented by SwiftUI fileExporter with a valid FileDocument. So "happens only during UI testing" in earlier replies is more precisely "happens only on parallel-testing simulator clones" — the local-storage file provider in a freshly cloned, test-hosted simulator appears unable to stage/write the document. The EXCLUDED_ARCHS workaround mentioned above doesn't apply in my case (project has no such setting). Workaround: run the affected test classes serially on a non-cloned simulator; everything else can stay parallel. (provided with AI, checked by human)

Same problem. It broke the devs entirely. This is worst thing ever... XCode Version 15.2 (15C500b) macOS 14.3.1 (23D60)

Confirm. Changing min deployment target to iOS 12 from iOS 11 solves the issue

Almost the same thing macOS 13.5.2 (22G91) XCode 15.0 (15A240d) iOS 16.6.1 (20G81) Crash on NWParameters init Now the whole project is broken

macOS 13.5 (22G74) xCode 14.3.1 (14E300c) Have the same problem. Need to restart Simulator every project run. UPD: when try to quit Simulator to relaunch it it fails with error: Details The operation couldn’t be completed. (Mach error -308 - (ipc/mig) server died) Domain: NSMachErrorDomain Code: -308 User Info: { DVTErrorCreationDateKey = "2023-08-08 08:15:21 +0000"; IDERunOperationFailingWorker = IDELaunchiPhoneSimulatorLauncher; } --

Try install rosetta: /usr/sbin/softwareupdate --install-rosetta --agree-to-license