Rakesh, nearly every post you put on here doesn't contain any details. In future please ensure you give as much information as possible!
Lucky for you I know what this problem is, in order for DevTools to work you need to create a folder named ".phalcon" without quotes in the project directory.
Hi mam, mkdir: cannot create directory `.phalcon': File exists Above Error I am getting when i try to create a folder
Make sure you don't have a file named ".phalcon", if you do delete it.
Once there is a directory inside your project directory named ".phalcon" the devtools will work.
hey thnx Rewt0r