Error when WF tries to change phase

Question

Hello experts!
We're setting up the WF's in ESO 5.1 for contracts.
However, when changing from one phase to another, we get the following error:
"The user [Username of Workflow Process Owner] is not authorized to monitor and/or approval of this document [test]. Please contact your administrator..."
Does this means that the user assigned as WF Process Owner needs to added to the document in the postscript phase?
If so, which role should it have assigned (we tried assigning as collaborator... it didn't work)?
If this is right, then it means that the WF Process Owner, which is actually a "system" account, will be receiving a whole lot of notifications... is this right?
I'll await your comments. Thanks!
Edited by: Gilberto Carlos Gallardo Millan on Oct 8, 2011 10:10 PM
This issue is now resolved. It seems when the WF entered the next phase, there was incorrect validation which was cancelling the process. I have no idea why this specific error was being sent, but after correcting the validation code, issue was resolved (so, in reality, it was not related to any authorizations).

Answer 1

What i can tell you after running BBP_BP_OM_INTEGRATE for business partner, employee role, i get the following : -
@5C\QError@     Error determining address for employee DD0A7F0F4A3D83F1AA8D0016353BF3FF     @5F\QNo long text exists@
and
@5C\QError@     Employee relationship between BP 0000004261 and BP(Org) 0000002669 missing     @35\QLong text exists@
The help says the following but i am sorry to say it means nothing to me : -
Employee relationship between BP 0000004261 and BP(Org) 0000002669 missing
Message no. BBP_UM_UI040
System Response
The assignments of the BP units of the employee &V2& -> Natural person of the employee (if necessary -> Contract) -> Work Center -> Position -> BP of the Position lead to BP &V1&. There is, however, no connection between the business partner objects.