Before upgrading you should read through the release notes of the new release, in case there are incompatible changes. If there are, there will be special instructions on how to upgrade.

Challenger is upgraded simply be installing the new version over the old one. This is done by doing a normal installation with your Challenger directory as target directory. See the Installation chapter for more information.

The installation script will first move the server directory to server.old and then create a new server directory for the new release. Since only program files are stored in server this won't affect any user configurations. This is why it is important not to install any third-party modules in server.

After completing the installation of the new release the running server must be shut down, by using the Shutdown/Shut down Roxen action. After that the new version can be started by running the start script, server/start. Everything should work out of the box.

If problems are encountered you can easily downgrade to the previous release by shutting down the new server, moving the server.old directory to server and running the start script again. If a server.old directory exists, it will be moved to server.older when you install the new release. If a server.older directory exists, it will be deleted. If you want to keep a particular Challenger release you should rename the server.old or server.older directory. It might not be as simple to downgrade to an older version after you have started using the new release.For example, there might be modules in the new release that were not present in the old one.