I have followed the suggestion of renaming cache and store, now getting the error code 16 with instructions to uninstall and reinstall. Which I have done several times already.
The error 16 means Lightroom cannot access the Folders Slcache and Slstore.
This normally happens if you do not have Read/Write Permissions for Adobe Folders.
Renaming them might not fix the problem
You need to provide Full R/w Permissions to Adobe Folder
Mention your Operating system and Lightroom version so that we can assist you better
Retrieving data ...