problem,please help

An error happened while processing the library GitHub - ARMmbed/mbed-os: Arm Mbed OS is a platform operating system designed for the internet of things. fatal: destination path ‘c:\Users\lenovo\AppData\Local\Mbed Studio\library-cache\github.com\armmbed\mbed-os.git’ already exists and is not an empty directory.

Hello,

your problem seems to be related to your PC and MbedStudio than to MbedOS directly.
So maybe better description of your problem could be good start.

BR, Jan