Unable to use iOS simulator below version 26 after installing Xcode 26 Beta 3

When I run xcrun simctl list in terminal, iOS 18.5 is listed in the runtimes. So the runtime has been downloaded, but Xcode can't find it. I installed it through Xcode, so I don't understand why Xcode can't find it.

I have the same setup as you: Xcode 16.4 with iOS 18.5, installed Xcode 26 beta 3, and my iOS 18.5 was removed.

However, when I closed Xcode 26, opened Xcode 16.4 and opened one of my projects, the run destination in the project window was an iOS 18.5 simulator but it said iOS 18.5 wasn't installed. I just clicked Get in the Xcode Settings > Components window and it all worked fine.

Can you open Disk Utility and look in the left-hand pane? At the bottom is a "Disk Images" section. I have "iOS 18.5 Simulator Bundle" and "iOS 18.5 Simulator" there, and they're both mounted. Maybe you've got the runtimes installed but somehow they aren't mounted?

I see both of those volumes in my Disk Utility, it appears that they are mounted.

Here's what I see under runtimes when I run xcrun simctl list: iOS 18.5 (18.5 - 22F77) - com.apple.CoreSimulator.SimRuntime.iOS-18-5 (unavailable, liblaunch_sim.dylib could not be opened)

I see: iOS 18.5 (18.5 - 22F77) - com.apple.CoreSimulator.SimRuntime.iOS-18-5 so that's why mine works fine.

I wonder if you can copy that file from somewhere else and put it into where it's supposed to be? Bit of a hack, but according to the internet people were doing this to fix this specific error.

Personally, I would remove the runtimes via Xcode, uninstall Xcode, remove the Developer folder in Finder (take any necessary backups), reboot, reinstall Xcode 16.4, reinstall iOS 18.5 and try again. It's a lot, but it should leave it all fresh.

I am having the exact same issue (only it was beta 2). I've cleared and reinstalled 16.4 and that did not fix the issue. I still cannot create any simulators.

18.5 shows up as mounted in Disk Utility but I get the same output from simctl list as chandler.dea.

The other part of this for me is that I cannot run most of my apps on my iPad (running 18.5). I get the following errors:

Assets.xcassets: No available simulator runtimes for platform iphonesimulator. SimServiceContext supportedRuntimes=[SimRuntime : iOS 18.5 (18.5 - 22F77) - com.apple.CoreSimulator.SimRuntime.iOS-18-5 (unavailable, liblaunch_sim.dylib could not be opened)]

LaunchScreen.storyboard: iOS 18.5 Platform Not Installed.

This has already cost me a number of hours and I am unable to do any development until this is resolved.

If only someone from Apple would actually read this forum post....

Update: When I run xcrun simctl -v, I get more details about why the runtime cannot be opened:

iOS 18.5 (18.5 - 22F77) - com.apple.CoreSimulator.SimRuntime.iOS-18-5 (unavailable, liblaunch_sim.dylib could not be opened) [/Library/Developer/CoreSimulator/Volumes/iOS_22F77/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS 18.5.simruntime] - Error Domain=com.apple.CoreSimulator.SimError Code=401 "The iOS 18.5 simulator runtime is not available." UserInfo={NSLocalizedDescription=The iOS 18.5 simulator runtime is not available., NSUnderlyingError=0x6000024e34b0 {Error Domain=NSPOSIXErrorDomain Code=86 "Bad CPU type in executable" UserInfo={NSLocalizedFailureReason=A Rosetta update is required}}, NSLocalizedRecoverySuggestion=Try reinstalling Xcode or the simulator runtime., NSLocalizedFailureReason=liblaunch_sim.dylib could not be opened}

The failure reason is interesting, I'm on a M4 Max, so I don't see why I could need Rosetta.

Okay, I finally fixed the issue. Installing Rosetta allows Xcode to use the iOS 18.5 simulator runtime. Here's the command: softwareupdate --install-rosetta

I didn't need Rosetta installed before I downloaded the XCode 26 beta the first time, so I don't know why this changed.

Awesome! This fixed my issues as well.