Xcode 6 playground error
I just installed Xcode 6 beta 6, but as soon as I create any playground I get the message "Playground execution terminated because the process stopped unexpectedly." I can't do anything without this dialogue instantly reappearing.
I can't find any reference to this or in the forums. Has anyone seen this problem?
MacBook Pro with Retina display, OS X Mavericks (10.9)