Finally found the solution. This link https://ubuntuforums.org/showthread.php?t=2501544.
SOLVED
The Solution:
Code:
$ dconf reset -f /org/gnome/desktop/
In case you want to backup your old dconf settings first:
Code:
$ dconf dump /org/gnome/desktop > dconfbackup.txt
Where dconfbackup.txt is the filename of your backup.
To restore the backup:
Code:
$ dconf load /org/gnome/desktop < dconfbackup.txt