How to Solve perl: warning: Setting locale failed

Today, on my ubuntu server I executed the following command to reconfigure MariaDB server.
sudo dpkg-reconfigure mariadb-server-10.0
A warning appeared on the screen.
perl: warning: Setting locale failed.
perl: warning: Please check that your locale settings:
LANGUAGE = "en_HK:en",
LC_ALL =...
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How to Solve perl: warning: Setting locale failed