When I open LR it says LR has encountered and error when reading from its preview cache and needs to quit. What can I do about this error and how do I fix it?
Lightroom says my preview cache is corrupted—how do I fix it? - The Lightroom Queen
Open the folder that contains your Lightroom catalog and delete the folder with the extension .lrdata. Then start Lightroom normally, and it will start building a new preview cache.
Retrieving data ...