Could not register 'chaotic-aur' database (database already registered)

[BluishHumility]

@Oskar

[chaotic-aur]
Include = /etc/pacman.d/chaotic-mirrorlist

# An example of a custom package repository.  See the pacman manpage for
# tips on creating your own repositories.
#[custom]
#SigLevel = Optional TrustAll
#Server = file:///home/custompkgs
[blackarch]
Include = /etc/pacman.d/blackarch-mirrorlist

#inclusión por gudari de AUR
[chaotic-aur]
Include = /etc/pacman.d/chaotic-mirrorlist

You may have added the Chaotic-AUR without realizing it is already included by default. Go ahead and delete the three lines on the bottom and you should be all set.