Unity: Sprite Packer enabling problem 2017.1.1f1

PROBLEM:
 I have completed all the process, Project setting: Packer Always enabled and When I clicked PAck button nothing happens. Also I have all my images tagged. When I create a new project and try this action even if I used the same images, the packer works, then I turn back to my old project and try to pack my images with the same working images but nothing has changed.

My icon folder (that I try to pack) path: Assets/Resources/icons

SOLUTION:

1. Move the assets outside the resource folder.Use path: Assets/icons
2. Disable and re-enable the sprite packer from the Project Settings > Editor
3. Close the project and reopen it