I got a note: The Legenda Child kit contains outdated copies of some of the Vauxhall templates. You may need to update these files to ensure they are compatible with the current version of the Walkers. You can see which files are affected by the System Status page. If in doubt, contact the design kit author.
Server environment: MySQL version: 5.5.44 – Recommended minimum requirement is MySQL version 5.6. See: WordPress requirements
What it mean?