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Upgrade to Ubuntu 18.04
Upgrade to JAVA 8 or 11
Upgrade to Apache Tomcat 8.5.x (latest) or Tomcat 9
Upgrade to MariaDB 10.3.x (latest packages on Ubuntu 18.04)
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Updating the Code
Update the WAR file and deploy
Data Fixes
Under admin → migrations, there is the ability to fix Enrolment Data (sets enrolled to based on MRP at the time), and to migrate to Contacts from relationships