Couldn't register xxx with the bootstrap server.

xcode4.6似乎有bug，以前点击运行从来不会出现程序启动不了或者crash的问题。

1. crash的问题

Couldn't register xxx with the bootstrap server.

出现这种情况，好像只能重启Xcode或者模拟器。再或者你每次先stop当前的，在运行。

其实这个报错已经很明显了：

Error: unknown error code.

This generally means that another instance of this process was already running or is hung in the debugger.

2. 程序启动不了的问题

failed to attach to process ID 0

http://stackoverflow.com/questions/12741188/error-failed-to-attach-to-process-id-0

我个人解决这个问题的时候直接从simulator里面删除掉刚安装的这个app。