Transferred photos to new external desktop drive to free up space on my Mac. When I rebooted the Mac the icon for Lightroom had returned to a generic apple icon and would not launch. Updates from CC will also not download. How do I re-download Lightroom from my CC account? Do I need to uninstall the remnants of the old Lightroom version that appears to be listed in the applications folder on the Mac? Will the re-download of Lightroom automatically launch with my existing photos and catalog?
As kglad suggested in the above post, that you should try and reset the Lightroom preferences first, if that doesn't work then you can remove Lightroom from your machine, restart the machine and then reinstall it from the creative cloud desktop app.
Also, It will not remove any of your images and you would be able to access the existing catalog( editing, rating, and images).
Let us know if that helps.