The run destination My Mac 64-bit is not valid for Running the scheme

The run destination My Mac 64-bit is not valid for Running the scheme

更新Mac系统到Mavericks后打开工程文件后，左边Project Navigator里面一片红色（frameworks）； 运行出现上面的弹框提示错误：

解决方案：（翔動聖絃提供）

How to change the SDK: 
1) Click on the project icon in the left hand panel. 
2) In the right hand panel that appears, select Build Settings » all. 
3) You'll see the option to change the SDK. Screenshot
4) 把Base SDK項改成ios 5.0