Iphone – Code signing error: Doesn’t match key pair in default keychain

I had the same problem: I first downloaded my certificates to my small MacBook while on the run. When trying to install the certificates on my iMac... then I ran into the problems described on this page.

After spending hours pulling my hair out like many of you, I performed the following steps to fix it:

1. Close all your stuff except your webpage that should be logged into App Dev center.

2. Open Xcode. Click WINDOW > ORGANIZER. Then click the Devices tab and select "Provisioning Profiles" on the left. That should bring up your provisioning profiles. Highlight one by one (if more than 1), right click and delete profile. Yes, just do it! Delete them all! (I kept making a new one after a new one trying to make the thing work.)

3. From the first page you see after logging into the App Dev Center on the right side click "iOS PROVISIONING PORTAL" > (do not "launch assistant"). Instead click on the left side. Select CERTIFICATES. You will probably have just one line listed with your name/company - from there click on the right side REVOKE. Click OK to verify that's what you want to do.

4. On the same page click DEVICES. Click the box next to your device you are trying to provision and click REMOVE SELECTED. Again click OK to verify.

5. Wait about 2 minutes to let Apple do their thing.

6. Now click on "HOME" that is on the left side navigation.

7. Click "Launch Assistant"

8. create a new app ID - call it whatever you want. Just make sure it's unique enough to know that's the one you just created because the others you've been messing with all day will not be deleted from Apples Dev Center.

9. You should be able to follow the rest of the Assistant without troubles -- the main thing is you just had to delete your old provision profiles and start over.

Good Luck!

This happens if you forgot to change your build settings to Simulator. Unless you want to build to a device, in which case you should see the other answers.