Proxy generation internal error

When I try to generate an ABAP proxy on my ERP client, I get the following error message when I check it:

"Proxy generation internal error: Object <message> Person Person_OB2(urn:acando:person) not found"

This happens with some other interfaces, but I have found one interface where this problem did not occur.

Can anybody shed some light on this?

Kind Regards,

Tony.