If you have installed Appeon 2016 or a later version, you can upgrade to Appeon PowerServer 2019, but you cannot upgrade from Appeon 2015 or an earlier version. If you are using Appeon 2015 or an earlier version, uninstall it and then install Appeon PowerServer 2019.

Note that applications deployed with the old version and the demo applications must be redeployed with Appeon PowerServer 2019 after the upgrade.