Annoying when mounting a disk Ask for Password on Debian (solved)

Run this command on the Terminal with a nano text editor

    sudo nano /usr/share/polkit-1/actions/org.freedesktop.UDisks2.policy

then search on the line  <action id="org.freedesktop.udisks2.filesystem-mount">
so at the end of this section you have to replace the word "auth_admin_keep" with "yes" 

like so

<defaults>

      <allow_any>auth_admin</allow_any>

      <allow_inactive>auth_admin</allow_inactive>

      <allow_active>yes</allow_active>

    </defaults>

Then save the file and let's see if works and open your File Manager. Good Luck mate.