You are using ISE 14.7, but the SDK Workspace was created using 14.6. Recreate the SDK Workspace using your current version.
I have removed all parts in the SDK Workspace and used the XPS (14.7 version) to regenerate the hw platform, then I imported the source codes (including the files: src, inc and lib) to the project and rebuilded it. But, the SDK still reported that there misses a "}" in the xil_cache.h and could not build the project.Then. I built an empty memory test project successfully without an error and this project contains the xil_cache.h. I have no idea which parts have gone wrong.