You can't edit a configuration that is already active on either Staging or Production. If you want to edit an active configuration, you must copy it and create a new version, then you can edit, save, review, and test if necessary. You can then submit the new version for activation. For more information, see Properties.
If you have previously activated two or more versions of a Property Manager configuration, you can view an XML diff by selecting the Diff Against vN link in the Currently Active row. This is a more advanced functionality for users who are familiar with the XML code that is used to implement the configuration.
Updated 11 months ago