Welcome to Adobe Forum,
Do you have beta(trial version) installed for light room? If yes, then uninstall it completely by checking the preference boxes too.
Now restart the computer & download & install from the CC desktop App. It should work.
In case it does not work, contact Adobe support at http://adobe.ly/yxj0t6.
Tks Rajshree, but the Lightroom I install at the CC desktop... It is not trial Lightroom, only the Lightroom mobile? is crazy no? kk.
Thank you very much Rajshree...