Hi Bharamani,
In general you'll want to apply any changes you've done to the old war to the new war. Often, the only file you had to change was the properties-local.xml, but you might have made changes or created other files.
If you're using the internal eXist and want to keep the data, you'll want to move the exist-data directory. If using a relational database, you might have to run some upgrade DDL at the database level. Search for "upgrade" on:
http://doc.orbeon.com/form-runner/persistence/relational-db.htmlFinally, here are some things to consider when upgrading:
http://doc.orbeon.com/configuration/advanced/upgrading.htmlAnd of course, just let us know if you have any question in the process.
Alex
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