DB Warning on startup: Establishing SSL connection without server's identity verification is not recommended.
After a migration from the DB (MySQL), in the log appear
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.
You have to use the parameter useSSL=false in the DB connection (the config can be found in ..\tomcat\webapps\ROOT\META-INF\context.xml)
E.g the url should look like:
This will supress this ssl errors. And Jahia will start correctly.