Guided Procedures with UWL

Ciao SDN,

I am trying to configure Guided Procedures with UWL.

I followed the guide How" target="_blank">https://www.sdn.sap.com/irj/sdn/go/portal/prtroot/docs/library/uuid/6b66d7ea-0c01-0010-14af-b3ee523210b5">How to..configure UWL with the GP engine

But when a user starts a task via UWL obtains the message:

<b>"Could not retrieve process instance: contact your system administrator"</b>

Someone can help?

Regards

Luca