Re: i would like to know that my lightroom 5 has suddenly stopped working... whenever i am launching it it is showing that lightroom has ecncountered a problem in reading the photos from its cache..plzz help me to slove this problm... as soon as possible.

Using your system browse go to the folder that contains your catalog. Delete the folder that has the extension .lrdata. This is the folder that contains your previews. After you have done that you can start Lightroom, and it will create a new preview folder and will begin to rebuild the cache.