PDO Layer error on Display Purchase Order

Hi,

We have our SRM7 system configured to send an email to the PO creator at the end of the approval workflow - this email has a link

to display the purchase order but when we click this link we get the following error:

"PDO Layer error"

I've checked through the notes and there's a few issues around the POWL queries, our POWL queries are working fine in the client

though and we can display the PO with no issues so I'm reluctant to change these. Is there a specific POWL that the email link uses?

The link is in the following format :

http://oursapsystem/nwbc/srm/~canvas;window=app/obn/po.display/?sap-client=500&SAPSRM_BOID=005056AA1D2…

The BOID corresponds to the correct GUID.

We are using NWBC for HTML, I've looked at roles/authorisations but not sure that's the issue as we can display the PO no problem within

SRM.

The following pdf describes it and recommends to implement PL18, we're on PL40.

https://websmp210.sap-ag.de/~sapidb/012003146900000494452011E/PDO_Layer_error.pdf

Seems like the "~canvas" tag is the issue?

Regards,

Tony