Users don't see Diagramm

Hi there, I think I did a mistake in the administration of my Camunda app. When a normal user opens a user task, the tab “Diagram” shows a text “Note there is no diagram available”. Only administrators can see the diagram. What did I do wrong? I can not find the authorization that prevents the normal users from seeing the diagram.

Many thanks in advance,
Christian

You need to give users access to the process definitions.