Xcode Error on Simulator: MGIsDeviceOneOfType is not supported on this platform

Question

I have a very simple application with a single view, containing several UILabels. Upon running in Simulator, the Xcode console returns the error:

libMobileGestalt MobileGestalt.c:875: MGIsDeviceOneOfType is not supported on this platform.

The Simulator itself just shows a white screen. I've also tried running it on a developer device with the same white screen. I've searched documentation but can't find any reference to MGIsDeviceOneOfType. The application is written in Swift in Xcode 10 beta on macOS 10.14. I am attempting to run it on the iPhone 7-X Simulators, as well as a development iPhone 7, all running the target software (12.0).

Answer 1

MobileGestalt

The libMobileGestalt.dylib provides a central repository for all of the iOS's properties. It can be analogous to OS X's Gestalt, which is part of CoreServices. OS X's Gestalt is documented for example Gestalt Manager and has been deprecated as of 10.8. MobileGestalt is entirely undocumented by Apple as it is a private library.

MobileGestalt allows for the testing of system properties that may or may not be compatible on different simulators.

Quite a few system processes and apps in iOS rely on MobileGestalt, which is located at /usr/lib/libMobileGestalt.dylib. It's more of a basic library, but its exposed APIs follow the Apple framework conventions and uses the MG API prefix for example MGIsDeviceOneOfType.

If you look for MobileGestalt on the iOS filesystem you won't find it - like all private frameworks and libraries, it has been prelinked into the /System/Library/Caches/...etc. If you like hacking and pen-testing then you can use tools to extract it.

MobileGestalt provides plenty of information - around 200 or so queries - on various aspects of the system. Here are a few.

libMobileGestalt.dylib
//Answers to MG queries

MGCopyAnswer(@"5MSZn7w3nnJp22VbpqaxLQ");
MGCopyAnswer(@"7mV26K/1a+wTtqiunvHMUQ");
MGCopyAnswer(@"BasebandAPTimeSync");
MGCopyAnswer(@"BasebandPostponementStatus");
MGCopyAnswer(@"BasebandPostponementStatusBlob");
MGCopyAnswer(@"BasebandSecurityInfoBlob");
MGCopyAnswer(@"BasebandStatus");
MGCopyAnswer(@"BuildVersion");
MGCopyAnswer(@"CoreRoutineCapability");
MGCopyAnswer(@"DeviceClass");
MGCopyAnswer(@"DeviceClassNumber");
MGCopyAnswer(@"DeviceName");
MGCopyAnswer(@"DeviceSupports1080p");
MGCopyAnswer(@"DeviceSupports720p");
MGCopyAnswer(@"DiskUsage");
MGCopyAnswer(@"GSDeviceName");
MGCopyAnswer(@"HWModelStr");
MGCopyAnswer(@"HasBaseband");
MGCopyAnswer(@"InternalBuild");
MGCopyAnswer(@"InverseDeviceID");
MGCopyAnswer(@"IsSimulator");
MGCopyAnswer(@"MLBSerialNumber");
MGCopyAnswer(@"MaxH264PlaybackLevel");
MGCopyAnswer(@"MinimumSupportediTunesVersion");
MGCopyAnswer(@"PasswordConfigured");
MGCopyAnswer(@"PasswordProtected");
MGCopyAnswer(@"ProductType");
MGCopyAnswer(@"ProductVersion");
MGCopyAnswer(@"RegionCode");
MGCopyAnswer(@"RegionalBehaviorNTSC");
MGCopyAnswer(@"RegionalBehaviorNoPasscodeLocationTiles");
MGCopyAnswer(@"ReleaseType");
MGCopyAnswer(@"SIMStatus");

There are hundreds more e.g. AirplaneMode, MobileEquipmentIdentifier, etc.

MobileGestalt maintains a table of OSType selector codes. for example c:890 in the message: libMobileGestalt MobileGestalt.c:890: MGIsDeviceOneOfType is not supported on this platform. In this case MGIsDeviceOneOfType is a method/property of the MobileGestalt library.

Instead of checking the simulator version there is a separate selector for directly querying the capabilities of the simulator. The messages most likely indicate incompatibilities between simulator versions and Xcode versions and/or unsupported APIs on the simulator.

Answer 2

I've successfully dropped it with the disabling of the project garbage.

Go to <Name of your Project>->Scheme->Edit Scheme Then go to Run (menu to the left side) and add the following environment variable:

Name:OS_ACTIVITY_MODE, Value: disable

Answer 3

in my case: check your app delegate for method - didFinishLaunching. I had private and get the error. After remove "private" everything works fine

Answer 4

I just installed Xcode 10 Beta and had the same problem. Ran Xcode 9.4.1 and the problem went away.

Answer 5

This error will only occur when testing/debugging on simulators.

The newer the simulator the better.

Case: I run simulator iPhone 8 plus I got this message in the debugger.

Solution: I changed to a newer simulator no error message in the debugger.

Answer 6

Ran into this when opening some project from GitHub on Xcode 10.0.

The pragmatic solution was: just hit 'Continue program execution' multiple times and probably disable your exception breakpoint. Apparently the exception was recoverable.

It's not a real solution but it was good enough for me at that point.

Answer 7

In my case, the Target's Deployment Target was at iOS 8. When I pushed it up to iOS 10.3, it ran fine, both on the Simulator and the device.

Answer 8

Am seeing this problem. Using Xcode 10.1. Created a brand new project - doesn't do anything except show a white screen. Discovered it was showing up on simulator for older devices. For example, iPad Pro (12.9 inch) and iPad Pro (12.9 inch) (2nd generation) show the problem, but problem is gone for iPad Pro (12.9 inch) (3rd generation). Does not show up for iPhone XR simulator.

Basically seems annoying.

Answer 9

If you have fonts provided by the app, you need to add to Info.plist And check if the file have the Target Membership selected

Answer 10

I had the same issue, but with MapKit, where a MapView did not show up, just the white screen and the same error, MGIsDeviceOneOfType is not supported on this platform.

Solved it by fixing "Ambiguous layout" warnings tied to the MapView object. Now it's working perfectly fine, and the errors went away.

Answer 11

The regular way when strange errors happens helped:

1) Clean project;
2) Shut down simulator;
3) Reinstall pods.

Xcode 10.

Answer 12

For me, with the simulator in question in focus, I selected Hardware->Erase all content and settings.

After the simulator restarted, launching my app worked again, as expected.

Answer 13

I went to XCode -> Preferences -> Components Ticked all the simulators and the check box to install updates automatically, and then "check and Install now" and went away for a few hours while they all updated.

Now the problem is gone - so in fact, it's as mentioned. New XCode with Old - non-updated simulators.

Answer 14

What worked for me was to change within general > Deployment Info > Main Interface to CDVLaunchScreen and do the same within general > App Icons and Launch Images > Launch Screen File to CDVLaunchScreen as well.

I come from Ionic, so this might not be a problem for those who develop in Swift / Objective-C.

Answer 15

I have recently updated to Xcode 10.2 and when I tried to run a project created in earlier version, Same error occurred.

The problem was that simulator was running before updating Xcode.

Solution was very simple for me to quit Simulator and restart so that it can get the new changes. I don't think the model of the simulator (iPhone SE or iPhone X) matters. You just need to restart your simulator for it to take effect of new update.

I would recommend to quit both Xcode and simulator and restart your Mac.

Answer 16

I got this error by calling .sync on the main queue which caused a deadlock (DispatchQueue.main.sync {}). I meant to call .async.

Answer 17

I got this error, when trying to read a json file which is inside my project and it returned nil, due to that i got this error.

I got nil because of some spelling mistake in the font name, that json file was holding the font names, after copy pasting the font name i got data and the error fixed.

I tried allmost all of the solutions given above, nothing worked, So debug with patience, you will get to know which is causing this error and in some bad time xcode will play in our life :)

Answer 18

I was facing same problem but I've successfully dropped it with below things:

1. Shutdown simulator,
2. Shutdown Xcode,
3. Re-open Xcode and simulator

I hope it will help.