I keep getting this issue spammed.

[02:18:39 WARN]: Fri Dec 28 02:18:39 GMT 2018 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification.

LuckPerms Version: 4.3.62 Bukkit/Spigot

Server Version: 1.12.2 (with viaversion, backwards, and rewind) (1.7-1.13.2)

The solution has been linked in issue #1235. It tells you precisely what you need to do. (What you need to add where).