I found the solution by myself after a couple of minutes but I think it would be better to share with the community. Here are the steps I followed:
- Download any .dmg disk image from the internet (I did cleanmymac x but anything should do it).
- Open it and click on the Applications folder shortcut Don't drag the file, you don't have to install it.
- On the applications folder that appears, drag the tiny folder icon from the window bar and replace the broken folder on the favorites bar located on the left
- If necessary, repeat it for the dock if it's broken there as well.
- Remove the old folder that doesn't work
- Either install, or unmount the Application you downloaded.
This is my first post and I really hope I helped.