The exchange scenario diagrams are exported in the XhtmlDocgen, there is no configuration on this. I would guess that this is related to your use of special characters.
Could you check that exchange scenarios diagrams not displaying objects with special characters (é…) are well exported ?
If this is the problem, then please fill a bug about this.
After creating a separate project for testing the export, I realized that the ES diagrams were included underneath the label “Diagrams displaying “System”” located within the tree path “System Analysis -> System”.
The same thing was for my project, so the ES diagrams exist and were well exported, except I didn’t notice that (sorry for that, I’m very new user).
Sorry for the inconvenience, and thanks for your help!