DIALOG variable error when posting with NAS a service order

Hello all,

Using a NAS service I try to post a Service Order, but I still got the following error:
You cannot use C/AL variables of type DIALOG when running the Microsoft Dynamics NAV Application Server.

I tried to add IF GUIALLOWED on each DIALOG or CONFIRM sequence of code from CU 5980, but the error still appear..

Can you give me a hint, pretty please?

Thx