No material was found for the selected objects

What causes this issue?

You have not selected any objects in the planning board that have had
material components allocated.

How to fix this error?

Determine which objects have material components allocated by choosing
<Ls>Extras -> Highlight object with assignments</> and then selecting
<ls>material components</> in the dialog box that appears.
Now select those objects whose matarial components should be shown.

Error message extract from SAP system. Copyright SAP SE.