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.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

The last packet successfully received from the server was 33,221,319 milliseconds ago. The last packet sent successfully to the server was 8 milliseconds ago.
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 unidata:Weblog|standard[line 17, column 64]
Type unidata:Weblog
Exception org.apache.velocity.exception.MethodInvocationException