I used Spotlight and removed (⌘ + Del and then "Empty Trash") all instances (files and folders) of Mozilla from my Mac to reinstall Firefox. Every time I reopen keep getting this error "A copy of Firefox is already open." I've done some Google searches to find some help, and it seems that it's been easily solved by removing a ".parentlock file." However, since I deleted all folders containing either "Mozilla" or "Firefox," I cannot find a ".parentlock" file even using ls -la and OnyX. Please help.