This WIKI describes how you can solve the error message shown when configuring the Floor Plan Management (FPM) for ESS, when using Web dynpro ABAP as below:
This error message doesn't allow the administrator to save or make any changes in the application configuration, thus making not possible to customize the Web dynpro.
First, it's presented when this message is shown, next it's given an explanation on why this behavior can occur, finally it's shown the solution for this issue.
The error message
The configuration done on the Application Configuration is to customize the Web dynpro in a way that if you perform upgrades or implement notes, this configuration is kept intact. This is done via SE80. Whenever you try to create or modify a configuration and click on the "Check" button, the message is displayed.
Why the error
Whenever you create a configuration for the Web dynpro, a new record is created into the database with a sequential Id. In certain cases, a next available Id number is not used, thus giving the error message that the element is not unique.
You need to edit the configuration and change the Id to the next available number.
To start this, you need to first append the parameter &use_default_editor=X on the URL which starts the default configuration editor, where you can edit all attributes of configuration context nodes.
Then you can change the primary attribute 'configID' of the configuration context element 'ess_Configuration' with configID 'KEY_CONFIG_189' (189 is the example ID used), to another non-existent 'KEY_CONFIG_xxx'. For this example, an attribute with 'KEY_CONFIG_189' did already exist, therefore the error occured.
You can use the following sample URL to do the changes:
(You may need to append the URL with the actual client number, i.e. &sap-client=XXX, where XXX represents the client number).
The Self-Service Application Metamodel - source: help.sap.com