10 Replies
      Latest reply on Jan 26, 2017 6:14 PM by IntoTheWoods
      jkwuc89 Level 1 Level 1 (0 points)

        I recently upgraded from Xcode 6 to Xcode 7 on my MacBook Pro running Yosemite.

        After opening a previously saved Swift playground, I attempted to make changes in it. More often than not, this results in the following error message and the playground does not execute.

         

        Failed to launch iOS stub for playground execution: error: attach failed: unable to attach.

         

        I tried creating a new playground and the behavior is the same. Eventually, making a change results in the error above.

         

        The only way to recover and it's only temporary because the error reoccurs is to stop and restart Xcode.