The Simulator can't be launched because it is already in use

Question

I'm working with xcode 5, and often get The Simulator can't be launched because it is already in use. when it's not running or open (i.e. after i do: quit simulator).

I stopped the application & don't have any other project that is open, running or using the simulator (please avoid these kind of suggestions).

this happens after i get and exception.

how can I "free" the simulator process without having to reboot my computer (right now that is the only solution i found) I've tried:

1. simulator -->services-->a reset content and settings
2. closing xcode and re-opening
3. xcode --> developer toos --> simulator -->(open the simulator) quit simulator
4. Activity monitor --> (the simulator is closed so nothing here to force close)

also the exception is not getting caught in any of my try catch so i wondering if which tool from the developer instrument can help me figure out what is wrong.

Corolla

I always do it by just closing the simulator app fully. .. I dont close xcode – Whelp

I think, that's a common bug. Just quit the simulator and try again. – Rosinarosinante

possible duplicate of iPhone Simulator Can't Be Lauched? – Rauscher

@MrVincenzo this is not a duplicate, as mentioned above,I only have one project open in xcode, and it's not running (cause i pressed the stop button). – Corolla

Have you found a solution to this problem yet? It's frustrating. It only goes away after restarting Mavericks ... – Diaphoresis

@Diaphoresis : quit xcode/ simulator and reopen again... that is the only weird solution... – Infrequency

@FahimParkar like all the solutions posted in the question, and other similar, I tried that. It seems to be fixed now with version 5.1.1 (5B1008) – Diaphoresis

The problem is solved here.... #22267453 – Rhetor

Answer 1

I got the solution..

1. First of all quit your simulator.
2. And then quit and restart Xcode.
3. And then run your project.

I hope it will help you...

Annabelannabela

I was able to get it working with just a regular quit of xcode, not a force quit, for what it's worth. – Trigger

@Busily Yes, I know its not a valid solution. It's a bug in xcode. – Annabelannabela

Yes this works, sadly I was hoping for a solution that did not require restarting xcode given you lose your undo stack. – Chesty

@DharmbirChoudhary simulator is the fast way for debug app. It don't mention resource sync problem. Ok, if don't mind resource sync problem. the real device debug is nice. but slow ~~~~~~~ – Busily

But not the prominent one, some times we need crtl+z but as we have restarted our Xcode, we can't do that. – William

This happens to me fairly often, I find if I quit the simulator then clean the project it usually works. – Oestriol

But.. I am afraid quitting Xcode will devoid me of any code changes I have to put back (cmd + z).. Especially when there are several changes in different files.. There has to be a different solution..!!! Unfortunately, only this works. – Holston

@Holston Yes. There should be different solution. But this is bug. So we can't do anything. – Annabelannabela

I have to keep redoing this every single time this message comes up, which is about 1/3 times I try to run my code. Agh! – Bolding

Can someone make script to force quit Xcode & simulator from console, or something? – Crack

This works for me, but with a ginormous code base, starting xcode takes minutes... sadnesss... – Nanine

#4. Restart your machine ;) – Tyro

Answer 2

Restart xcode and the simulator. It's a bug.

Intravasation

Answer 3

What might be going on here is that you've terminated the simulator, but you haven't actually terminated the debug session that Xcode still has open with the simulator. You'll notice that the stop button still appears in the top left. The debug session remains open because you never continued from the exception you hit.

You'll be able to kill the debug session by pressing the stop button, or by pressing command+period. After that, you'll be able to build to the simulator again.

Bathymetry

This may be the case, but not always. I just had the "simulator cant be launched" error after stopping the simulator without hitting any breakpoints or any exceptions. It looked like a clean close. The stop button was disabled and the debug menu (Pause, Continue etc) was disabled, because I was no longer debugging. Only closing Xcode and the Simulator helped. – Stout

Answer 4

Once we get the error of "Simulator in Use", we will be left with no other option than quitting the Xcode and so the changes made in the code cannot be undone.

The only solution which I came across, is to make a habit to_

1. Clean the Project twice or more times

2. Reset the simulator before running the project.

And the worst part of this solution is to follow this procedure each time before you want to run the project in simulator.

But it does not require to Force Quit Xcode and so this atleast allows us to undo the changes in the code.

Can't help it fellas...

This Bug needs to be resolved by apple, I guess...

2nd September,2014.

I am not facing this problem since i updated my Mac OSX and Xcode. Seems like it is fixed by Apple.

Thanks fellas.

Shaduf

I still get this - 27th Jan 2015. Latest Xcode, latest OS X. – Lippizaner

I don't know why, but i stopped getting this maybe because I made a practice of deleting derived data regularly before starting it everyday and resetting the simulator everytime I run my project. – Shaduf

Answer 5

Try doing a reset content and settings

Oddfellow

+1 Fixed it for me. Merci. – Ceram

Has worked for me sometimes in the past, but not always. – Stout

Answer 6

You just need to close XCode and the iOS Simulator apps. Then restart XCode. That's it.

Dixson

Answer 7

You can also fix this by clicking stop button ( next to play button ) on upper left part of xcode. The problem is the simulator is / may be stopped but the debugger is still running on the file. So instead of restarting xcode, just click stop button.

cheers

Speller

Answer 8

Check if another instance of Xcode uses the simulator. If so just stop the running application by pressing the rectangle on the top left corner of Xcode. It always happens to me because I forget to close the application that is running.

Prototherian

Answer 9

Check the dock of MacOS, can you find the the simulator icon? Then to check the bottom of the icon whether there is a white line or a white point. If you dock is not at bottom, check the left or right side of the icon whether there is a white line or a white point. If have, the simulator is already in use. You should click on the simulator icon, then press cmd+Q to quite it.

Marnamarne

Answer 10

I tried above all but they could not help me to solve my issue. I removed the Xcode and installed it again then the problem is solved.

Make sure that you have installed Xcode properly otherwise Xcode will not work properly.

Rhetor

Answer 11

I think it a bug in Xcode 5.1

and i use this solution for this issue. "Close all application from background and then run"

To close application from background use,

Select simulator then press "Ctrl+Shift+H+H" So it open background task screen in this close all application from background and then run your application from Xcode.

i hope this will solve you lots of time of restarting the Xcode.

Rica

Answer 12

I hav the same problem. My way to slove it is simple: select the correct simulator from simulator's menu->hardware->device. seems the problem is becasue the simulator device didn't fit the scheme device in the xcode project.

Wheaten

Answer 13

Check every project window, click "Stop running" button on the top left of XCODE.

Chemiluminescence

Answer 14

No need to stop Simulator. * Stop debugging all other projects in Xcode. * Now Run your desired application.

This worked for me.

Undersecretary