Velocity Template Error

Exception Velocity template error : standard
Message Invocation of method 'getStylesheet' in class org.apache.roller.weblogger.pojos.wrapper.WeblogWrapper threw exception javax.persistence.PersistenceException: Exception [EclipseLink-4002] (Eclipse Persistence Services - 2.7.5.v20191016-ea124dd158): org.eclipse.persistence.exceptions.DatabaseException
Internal Exception: com.mysql.cj.jdbc.exceptions.CommunicationsException: The last packet successfully received from the server was 340,885,106 milliseconds ago. The last packet sent successfully to the server was 340,885,115 milliseconds ago. is longer than the server configured value of 'wait_timeout'. You should consider either expiring and/or testing connection validity before use in your application, increasing the server configured values for client timeouts, or using the Connector/J connection property 'autoReconnect=true' to avoid this problem.
Error Code: 0
Call: SELECT id, action, description, hidden, updatetime, link, name, navbar, outputtype, websiteid FROM weblog_custom_template WHERE ((websiteid = ?) AND (action = ?))
bind => [2 parameters bound]
Query: ReadAllQuery(name="WeblogTemplate.getByAction" referenceClass=WeblogTemplate sql="SELECT id, action, description, hidden, updatetime, link, name, navbar, outputtype, websiteid FROM weblog_custom_template WHERE ((websiteid = ?) AND (action = ?))") at asf:permalink|standard[line 7, column 76]
Type asf:permalink
Exception org.apache.velocity.exception.MethodInvocationException