Error opening iOS Simulator with iOS 8 beta version: “Unable to boot the iOS Simulator”

Question

I recently installed the beta of Xcode Version 6 in OS X Mavericks, with which comes the iOS simulator for iOS 8. I've managed to successfully run from Xcode 6 beta on a device with iOS 8 Beta, but opening the simulator always get the same error I have tried to change the hardware version of iPhone 4s, iPhone 5, ... in the simulator and still gives the same error: "Unable to boot the iOS Simulator".

I'm working with Xcode 5.1 at the same time in Mavericks, any suggestion to solve this? Is a possible problem for run this simulator in Mavericks because is only for OS X 10.10? Thanks.

Answer 1

After I found some solutions on the web, a combination of procedures worked for me:

1. Close Xcode and iOS Simulator (and all related applications)

2. Install (or reinstall) Xcode6-Beta to Applications folder (direct from the .dmg file)

3. Open Xcode6-Beta and go to Xcode -> Preferences -> Locations -> Command Line Tools and select "Xcode 6.0" (be sure that you've selected the one in Applications folder)

4. Launch the iOS Simulator and go to iOS Simulator -> Reset Content and Settings...

5. Close all the applications and restart your mac (I unchecked "Reopen windows...")

6. Open Xcode6-beta and test the iOS Simulator

Good luck

Answer 2

I also had this problem and found the solution by doing following steps:

1. Initially i downloaded Xcode 6 library in Documentation section under the path Xcode --> Preferences --> Downloads and restart my xcode but didn't solve my problem.

2. Downloaded and installed the iOS 7.1 Simulator under the path Xcode --> Preferences --> Downloads. Restart xcode again and the problem solved.

3. I am facing same issue again next morning. Unsetting the DYLD_INSERT_LIBRARIES variable solves my problem:-

   1. Open terminal and type "sudo vi /etc/launchd.conf" command and press Enter

   2. Press I "Insert" mode and change this

      "setenv DYLD_INSERT_LIBRARIES /usr/lib/libimckit.dylib" 
      

      to this

      "unsetenv DYLD_INSERT_LIBRARIES /usr/lib/libimckit.dylib" 
      

   and press esc to exit from insert mode.

   3. Save changes by typing ":wq" Press Enter
   4. Reboot your system and problem soloved.

---

Prior to that I didn't find any iOS version in front of each listed devices but after installation or by unsetting DYLD_INSERT_LIBRARIES variable I found the same in front of each device.

Answer 3

I solved by removing and re-adding the simulators see screenshots here.

https://stackoverflow.com/a/25387715/1565615

Answer 4

I don't believe your issue is related to running Xcode 6 in Mavericks, as I encountered the same error on OS X 10.10.

After a bit of toying around with XCode and the iOS Simulator, the only fix I found was simply restarting the computer, and the error hasn't appeared since.

Try a reboot and then see if you can get things up and running.

(On a side note, after restarting just XCode (not the OS), I lost the option to run on the simulator at all—the reboot also fixed this problem, if anyone here encounters anything similar).

Answer 5

In Xcode go to the Xcode menu->Open Developer Tool - IOS Simulators. Choose simulator and then go hardware->device->manage device.

If the troubled device shows in the left column, delete it. Then add the device back from the '+' button. If it wasn't there in the first place, simply add it using the '+' button.

Answer 6

I had previously deleted ~/Library/Developer/CoreSimulator/ directory and the only command that worked for me is xcrun simctl erase all. Perhaps you might want to give this a try.

Answer 7

I've faced same issue and solved by below steps:

1) Move xcode6-beta into application folder

2) Restart mac and open xcode6-beta from application folder.

Answer 8

i too had the same issue, but solved by installing the required simulators (Xcode > Preferences> downloads > install simulators)

Answer 9

This happened to me running the simulator on both Xcode 7 and 8 on El Capitan. The only thing that worked was disabling System Integrity Protection (https://apple.stackexchange.com/a/208481/86757).

Answer 10

I tested an awful quantity of solutions and the only one which worked for me was disabling root protection through Recovery Mode. I tested it with XCode 7.3, it's possible that this approach may work for XCode 8.

• Reboot and hold the keys cmd + R prior to show the loading view with Apple Logo
• When you are on Recovery Mode, go to Menu and choose Terminal
• Type csrutil disable
• Reboot the machine and run the simulator again.

Answer 11

I am adding this answer as it seems to be slightly different from the others.

Due to working on an older project I needed to download and run Xcode 7.3 and load the project in simulator - this yielded the "Unable to boot the iOS Simulator" error.

I completed all the above suggestions and none of them worked (reset simulator setting, restarted, deleted and reinstalled Xcode, reset the simulator location, restarted again etc)

In the end the issue was that I was trying to load the iPhone 5 (10.0) simulator on Xcode 7.3.

You can see here the Apple release notes for Xcode 7.3

Xcode 7.3 requires a Mac running OS X 10.11 or later.

Xcode 7.3 includes SDKs for iOS 9.3, watchOS 2.2, OS X version 10.11.4, and tvOS 9.2.

As you can see Xcode 7.3 doesn't include an SDK for iOS 10.0

This meant as soon as I loaded the simulator with iPhone 5 (9.3) it worked immediately.

I would therefore recommend when approaching this issue not to get railroaded (as I did) in thinking that something is wrong with the system before checking the basic things.

Note: It is also worth noting that the simulator must be configured to the Xcode version being used. This can be set in

Xcode -> Preferences -> Locations -> Command Line Tools

and also using the command line:

sudo xcode-select --switch /Applications/Xcode_7.3.app/Contents/Developer

*change the Xcode version to the new one you want to use

Answer 12

one of the reasons could be you might deleted /private folder.

you can try with following commands

sudo mkdir /private/tmp 
sudo chmod 1777 /private/tmp

Answer 13

Following are the steps for solved above issue:

1. Search launchd.conf file in your mac

2. If not found then create from Terminal with help of command

~ user$ sudo touch /etc/launchd.conf

3. Terminal will ask you machine password

4. Then Open created file with help of command for EDIT, if terminal give you error as permission failed

~ user$ sudo /Applications/TextEdit.app/Contents/MacOS/TextEdit /etc/launchd.conf

5. Open file manually from /etc/launchd.conf (Shift+cmd+g) and enter /etc/ (TextEdit software)

6. In file "DYLD_INSERT_LIBRARIES" flag replace with "ZZ" and save it.

7. Restart your machine.

8. Xcode will defiantly works.

Answer 14

This error indicates an error starting up launchd_sim when booting the simulated device. In and of itself, it does not indicate the actual cause. You can look in ~/Library/Logs/CoreSimulator/CoreSimulator.log for more information about the error (including the error reason).

Possible causes:

1. On OSX 10.9 and earlier, DYLD_INSERT_LIBRARIES could be set by 3rd party applications. On later versions, invalid DYLD_INSERT_LIBRARIES are ignored instead of resulting in an error.

2. Usage of older simulator runtime DLC with Xcode 7 betas. Newer versions of Xcode ignore these older DLC.

If you need additional help, please provide that additional datum.

Answer 15

Just check your simulator's iOS version. I fought with this error for 2 days and tried everything. Once I run the project on the simulator with iOS version that my Xcode supports, it worked sadly... :/

Answer 16

I quit everything and restarted the Mac. That's all. Its worked like charm!!

Answer 17

I don't know why, but this happened to me when I had Charles Proxy's throttling turned on.

I didn't have to run Xcode again or clean anything. Just disabling the throttling allowed the simulator to work again.

I also clicked on details, but this was all that I got:

Details

Unable to boot the Simulator. Domain: NSPOSIXErrorDomain

Code 60

Failure Reason: launchd failed to respond.

This might be related a known Xcode 11.2 issue:

Third party “endpoint security” software may cause slow simulators, system freezes, or prevent debug processes from running in simulators reliably. This sometimes manifests as debugserver disconnections or simulator applications receiving a SIGKILL signal. (55853555)

Workaround: Uninstall the third party software.

Though I was seeing this error on 11.1. Yet Apple may have just not realized this was an issue on 11.1 as well ¯_(ツ)_/¯

Answer 18

I have solved this issue using following steps:

Xcode -> Preferences -> Location -> Derived Data -> Delete your project folder.

Answer 19

I got this error on OS Catalina, Xcode 11. I solved this by simply quiting simulator and Xcode, and then start Xcode and run your application.

Answer 20

Late answer, but it maybe helpful to someone. I tried all the solutions provided in this and related posts and neither of them worked.

I am using OSX(version 10.10.3) and Xcode 6.2. To fix this issue I followed the following steps :

• Delete all xcode and simulator related files using AppCleaner.
• Restart Mac.
• Open Disk Utility app from applications.
• In Disk Utility app; click on button Verify Disk Permission for your Macintosh HD (there will be some warnings displayed; I think /private/tmp is cause of this issue).
• In Disk Utility app; click on button Repair Disk Permission for your Macintosh HD.
• Re-install Xcode; now it should work.

More info : How to fix Xcode error ‘Unable to boot iOS Simulator’.

Answer 21

This may helpful

• Open simulator with 4s
• Click on menu- iOS simulator
• Click on Reset content and settings...
• Force close the simulator and run app.