cProjects 4.0 || Communication with WFM-Core not possible

Hello Experts,

we run cProjects 4.0 on a ECC 6.0. Status-Information shows that WFM add on is installed.

But every time cProjects is started the error appears 'Communication with WFM Core not possible'. Therefore I can't assign project roles to my project.

The description of the error says that an RFC Connection problem exists with WFM. But where I can maintain this RFC Connection.

Thanks a lot for your answers.

Regards

Kruno