Help! LR5 was working just fine on my Mac until this morning, when I get a box that reads "Lightroom encountered an error when reading from its preview cache and needs to quit. Lightroom will attempt to fix this problem the next time it launches". I've tried everything I can think of....I cannot get it to launch. It won't let me do anything other than click "OK", and then it closes.
It seems that the preview files have got damaged. Please follow the below steps.
> Please navigate to the location of your catalog file.
Default Location of Catalog
Note : Location and catalog name may vary if you have created your own catalog in custom location
> Rename Lightroom 5 Catalog Previews.lrdata to old.Lightroom 5 Catalog Previews.lrdata
> Restart Lightroom
Hope this helps