I upgraded my MySQL version from 5.5 to 5.7 and in phpmyadmin I get this error message. I tried to reinstall and reconfigure it but I have still this problem. Can you help me? I am using Linux Mint. Thank you
It takes two steps. You must upgrade from 5.5 to 5.6 and run mysql_upgrade, then do 5.6 to 5.7.
When you are upgrading best practice is to upgrade to the next available version i.e just upgrade from 5.5 to 5.6 using mysql_upgrade , you can do in place upgrade or you can take entire database dump and install a new service and restore the backed up database there. and once you move to 5.6 upgrade it to 5.7 version.