just downloaded the latest version of light room and installed it however it does not work when you click on the icon nothing happens. However the old version of light room is still there and works fine. This is the first time I've ever had to contact Adobe tech support and I am not impressed, it his been hours and my chat is still just sitting there doing nothing, cannot get anyone on the phone and no way to email.
If you're using the CC subscription service have you tried logging out of your CC desktop app, then logging back in again? Quit/Restart won't work, but logging out and back in should. See here: https://helpx.adobe.com/creative-cloud/kb/sign-in-out-creative-cloud-desktop-app.html