1. iOS APP Project or  Mac APP Project编译错误提示：

“The run destination My Mac 64-bit is not valid for Running the scheme '***'.The scheme '***' contains no buildables that can be built for the SDKs supported by the run destination My Mac 64-bit. Make sure your targets all specify SDKs that are supported by this version of Xcode.“2.  问题原因：工程设定的SDK Version和PC上安装的Xcode对应的Mac or iOS SDK Version不一致。3. 解决办法：Solution，to change the Base SDK Version: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 "Base SDK". Architectures » Base SDK.4) change Base SDK option to your project corresponding SDK version, OS X SDKs or iOS SDKs.  eg: OS X 10.8 or iOS 6.0.