Today I moved to the latest version of Xcode (4.3). I tried to open an old project and when I try to launch the iOS simulator it returns me the following error:
Xcode cannot run using the selected device. No provisioned iOS devices are available with a compatible iOS version. Connect an iOS device with a recent enough version of iOS to run your application or choose an iOS simulator as the destination.
I also tried to create a new project and there I am able to launch the simulator.
How can I fix this problem and run all my old projects again?