EXCEPTION | iamquestion
  How to fix IllegalArgumentException occurred calling getter of id ?
  how to fix NoSuchBeanDefinitionException: No bean named 'springSecurityFilterChain' is defined ?
  How to fix java.net.UnknownHostException: tiles.apache.org ?
  how to fix javax.management.InstanceAlreadyExistsException ?
  The processing instruction target matching "[xX][mM][lL]" is not allowed.