You can choose to install and configure additional AEM Forms on JEE modules at a later stage. On configuring additional modules (For example, Output and Correspondence Management) at a later stage, AEM Forms configuration manager fails to connect to JVM and the installation is not successful.
When you install and configure AEM Forms with a non-root account and run the underlying application server with root account to configure additional modules, the configuration manager can fail to connect to JVM.
To resolve the issue, use a fresh copy of the application server and re-configure the AEM Forms instance. General instructions to use fresh copy to reconfigure an AEM Forms instance are: