When creating or modifying layouts in Designer, you cannot change objects' properties due to missing Properties, DocumentTree, and DataSources panes.
Reproducing the issue
In the rendering engine Designer, select or create an object on the layout.
Panes with the names Properties, DocumentTree, and DataSources are missing and you are not able to edit any object.
Editing of objects is possible via appropriate panes.
The issue is in the 3rd party product rendering engine.
As a workaround, please delete the following file to reset the properties of the rendering engine: