I just found how to solve this problem.

 1. Go to the `/System/Library/Sandbox/Profiles` folder, you will find a file named `fmfd.sb`. You can't modify it here, so copy it to your desktop.
 2. Open the copy with TextEdit, locate the `allow file-read-metadata` section and add a new line under `(literal "/Volumes")` for the folder that can't be read, for you that should be `(literal "/Volumes/Macintosh HD")`.
 3. Replace the original with the copy (don't forget to make a backup), since it's in a system folder it will ask for your password.
 4. Reboot your Mac the error messages in Console should be gone!