i am not able to open the LR 6 , every time time i am trying to open i am getting this massage the lightroom caralog named "lightroom Catalog" cannot be opend becuase anothe application alrady has it opend .
When Lightroom is running, a .lock file is created to prevent other users from opening the catalog, and when you close the program, this file is deleted.
If the program crashes or isn't closed properly, the .lock file isn't deleted, and will prevent you from opening the catalog.
Use Windows Explorer/Mac Finder, and go to the folder containing the catalog - usually in the Pictures/My Pictures folder.
Delete the file with the extension .lock. Don't delete anything else. Now try to launch Lightroom.