error "Cannot recognize the target platform; are you targeting an unsupported platform?"

Project before using the coco2d-x 2.0.2 developed, and now I was asked to replace the 2.1.0 version of the-X
In the original project in the lib folder to delete the following things to replace the latest following error occurs during compilation, seeking solutions.
error "Cannot recognize the target platform; are you targeting an unsupported platform?"
Reply:
Estimated Base SDK version and target platform version of the problem, try using a different version under.
Reply:
Solved, completely remove the old version of the previous-x, reinstall the new version-X to open the program run the compiler.