iPhone simulator hangs immediately upon launch

Whenever I try and launch the iphone simulator (via Build & Run) in Xcode, the simulator shows up and immediately hangs with the beach ball.

I've tried Building and running a blank project, restarting Xcode and my machine, and so far nothing has helped. I am running Snow Leopard 10.6.5, Xcode 3.2.5, and Simulator 4.2.

The only errors showing up in my console are:

12/11/10 6:03:02 PM installd[1134] CFPreferences: user home directory at file://localhost/Users/Old%20Mac/Library/Application%20Support/iPhone%20Simulator/4.2/ is unavailable. User domains will be volatile.
12/11/10 6:03:42 PM com.apple.launchd.peruser.502[117] (com.apple.iPhoneSimulator:com.apple.mobi开发者_开发知识库le.installd[1155]) Exited with exit code: 255
12/11/10 6:03:42 PM com.apple.launchd.peruser.502[117] (com.apple.iPhoneSimulator:com.apple.mobile.installd) Throttling respawn: Will start in 10 seconds

The simulator stays frozen at the black screen:![frozen!.]

Any help would be much appreciated—thanks!

Had the same problem, with a fresh install of the latest SDK (iOS Simulator loading forever with a black screen, also with the original Xcode templates).

Here's were you find the solution: https://discussions.apple.com/thread/2611612?threadID=2611612. Deleting /Library/Application Support/iPhone Simulator worked for me. IOS Simulator then re-creates the folder whilst quitting. In addition to "/user/..." it then contains a directory "/4.3/...".

Open the iOS Simulator which is showing the black screen tap on it then you would be able to see the iOS Simulator menu on the top

iOS Simulator -> Reset Contents and Settings should work

In case you are using a dual graphics Mac (like a MacBook Pro) this also sometimes happens if vide system cannot switch to the discrete card. Resetting SMC fixes the issue: http://support.apple.com/kb/ht3964

I restarted my Macbook Pro and that fixed it for me.

Are you logged in as the same user specified by the path otherwise there can be permission problems? Perhaps you could try to reinstall xcode.