"Customizations are disabled for the node xxxx because it is not part of the project contentset". This warning is logged if you try to open a node for customization in customizaion role IN FA environment from Application Resources->connections->customizable archive ,
as this node is not a part of project. In order to add it to the project you will have to right click on the node and select customize this will add the node to the virtual content set of project.
Now this node will be available under project and can be customized.