Could not launch process launch failed: timed out waiting for app to launch

Question

I had this problem when I used a Distribution certificate instead of Developer one when running the app from Xcode. You may check it out your target --> Build Settings --> Code signing.

As @AndyDynn pointed out in his comment: Make sure you do this on the "Target" build settings and not just the "Project" build settings.

I literally restarted my iPad, that was connected for testing the app, and that resolved the issue.

To run your app on a device, you will perform these tasks that follow:

1. Request a development certificate.

2. Add your device to the portal.

3. Code sign your app.

4. Launch your app on the device.

For more detail check this

If your provisioning profile and code sign everything is alright then try once Quit and Restart your XCode. It will work for me.