Could not attach to pid : “####” unable to attach [duplicate]

Question

I just updated to Xcode 7.3.1 and my project crashes with the same error after the launch screen displays on the iOS simulator.

The error is:

"Could not attach to pid : “1712” unable to attach"

Then I tried running another project and I got:

"Could not attach to pid : “2025” unable to attach"

Any solutions?

Mauricemauricio

did you try clean, rebuild, restart? – Daubery

Wish any of the below answers would work for me :( – Pilose

None of the answers on this page worked for me. I found a solution involving attaching to the process already running in the simulator. This page no longer allows answers, so I am putting the details here: https://mcmap.net/q/187629/-failed-to-attach-to-process-id-xcode – Siegfried

I had the problem because of slow internet connection – Daystar

De-Selecting Debug Executable option under edit scheme fixed it for me! – Sheets

Answer 1

Resetting the content and settings in the simulator worked for me. This is available on the iOS Simulator: Hardware -> Erase all Content and Settings

Geddes

in most of the cases, this is actually the correct answer. – Gastrotrich

The menu item is now called Hardware -> Erase All Content And Settings. – Mukul

The menu item is now called Device -> Erase All Content And Settings – Divisive

Answer 2

Kill the simulator, then re-build.

Devitt

Actually, you don't even need to kill the simulator, re-building make it work for me. – Afterguard

I usually just re-run it. But re-building is what's intended here. – Wherever

None of these worked for me. killing the simulator, deleting the app, switching simulator, rebuilding, deleting derived data, cleaning build folder, cleaning project, none worked. – Kendrick

Answer 3

1. I closed Xcode.
2. On the simulator menu: go to Hardware -> Erase all content and settings.
3. Open Xcode then build and run the application.

The above simple steps worked for me.

Eyla

The order of the steps as shown here solved it for me. – Sleety

Answer 4

1. Close Xcode & simulator
2. Reopen Xcode & rebuild

Above steps worked for me.

Vaillancourt

Answer 5

In my case Xcode 8.0 after this error,just rebuild again project it solves this problem.

There is no need for reset app content in iPhone device.

Cauterize

Answer 6

Clean the project,quit the simulator and then rebuild the app

Larios

Cleaning the project and then running always make the trick for me. – Invercargill