Error with iOS Simulator (IBSimDeviceType.iPad3x) in Xcode 16.3 / Flutter 3.29.3

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1

Hello everyone,

I’m facing a consistent issue with running my Flutter app on iOS simulators. No matter the iOS version (16.4, 17, 18.4), I always get the same error and cannot run my app. My current setup is:

  • Flutter: 3.29.3 (Stable Channel)
  • Xcode: 16.3
  • iOS Simulators: Tried multiple versions (16.4, 17, 18.4), same issue persists.

The issue:

Whenever I try to run my app on any iPhone simulator (iPhone 14, 15, or 16) with different iOS versions (14/15/16), I encounter the following error:

Failed to find a suitable device for the type IBSimDeviceType.iPad3x (com.apple.dt.Xcode.IBSimDeviceType.iPad-3x) with runtime iOS 18.4 (18.4 - 22E238) - com.apple.CoreSimulator.SimRuntime.iOS-18-4

This error prevents me from launching my app on the simulator, and I’ve tried the following steps to fix it:

What I’ve tried so far:

  1. Cleaned the Flutter project:
  • flutter clean
  • Removed Pods, Podfile.lock, and re-ran pod install in the ios/ directory.
  • Cleared DerivedData using: rm -rf ~/Library/Developer/Xcode/DerivedData.
  1. Fixed the app icons:
  • Verified and updated the icons in Assets.xcassets, ensuring all required sizes for both iPhone and iPad are present.
  1. Tried multiple simulators:
  • Tested on iOS 16.4, 17, and 18.4 simulators, but the error persists across all versions.
  1. Device selection:
  • I selected iPhone 14 as the target device, but the issue happens regardless of the simulator runtime (16.4, 17, or 18.4).

This issue started occurring after updating my setup, including the Flutter version and Xcode version. Before the updates, everything worked fine, and I was able to use hot reload and run the app on the iPhone simulator without problems.

What I’m looking for:

  • Has anyone experienced the IBSimDeviceType.iPad3x error when trying to run a Flutter app on an iPhone simulator?
  • Is there a specific solution or workaround for this issue, especially for Flutter users running Xcode 16.x and the latest iOS simulators?

My goal is to get back to my normal workflow with hot reload and running the app on the simulator without facing these errors.

Any help or guidance would be greatly appreciated!

2

Does this happen with every app? Like the default example counter app?

3

I just tested with the default Flutter counter app (flutter create myapp), and I got a LaunchScreen-related error right after running it — not the same IBSimDeviceTypeiPad3x error.

However, in my other ongoing Flutter projects, I do get the exact same IBSimDeviceTypeiPad3x error when trying to launch them on the simulator.

So it doesn’t happen only with one project, the issue seems to affect multiple apps on my setup.

4

Did you try removing and adding your simulators again?

You can try to remove iOS component entirely from Xcode and then install it again.

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You can also try to clean the Xcode cache (e.g. with apps like DevCleaner)

5

Thanks for the suggestions. Here’s what I tried:

– I removed and re-added the simulators manually
– I deleted ~/Library/Developer/CoreSimulator and ~/Library/Developer/Xcode/DerivedData
– I used DevCleaner to wipe Xcode’s cache and restarted the machine
– I re-downloaded the iOS 18.4 runtime in Xcode settings
– I ran flutter clean and regenerated icons using flutter_launcher_icons

Despite all that, when I build with Xcode or Flutter, I still get the same error that I didn’t had before updating pointing to Assets.xcassets complaining about IBSimDeviceTypeiPad3x, which isn’t part of the generated icons.

6

did you open an issue on github?

7

yup Xcode build fails with error related to IBSimDeviceTypeiPad3x in Assets.xcassets · Issue #168902 · flutter/flutter · GitHub