While replicating PurchaseOrderExportRequest or other documents from Ariba Procurement (P2P), I can see the error below in the SAP Integration Suite, Managed Gateway for Spend Management and SAP Business Network:

A sequence of more than one item is not allowed as the first argument of fn:substring() ("abc@dummyhost.com", " abc@dummyhost.com ")

You have mapped a field in SAP Integration Suite, Managed Gateway for Spend Management and SAP Business Network mapping tool to an item segment using a substring function and have not added a loop, so the mapping is not considering subsequent items.

You need to add a loop to the item segment to make sure that the mapping is applied for all the subsequent items:

1. Log in SAP Integration Suite, Managed Gateway for Spend Management and SAP Business Network.
2. Click My Configuration > Mappings.
3. Click in the pencil button for the document type that you are facing the issue.

Now you are in the mapping for this specific document type, do the following:

1. Click with the right button in the line of the mapping that you are performing to the item segment.
2. Click Target Variable > Position and click in the item segment from target structure(appears in the right side of the screen).
3. Repeat the step 1 but this time click Add Source Condition.
4. Click in the father segment of the field that you are mapping from the source structure(appears in the left side of the screen).
5. A pop-up will appear, click Position Variable.

SAP Integration Suite Managed Gateway > Managed Gateway for Procurement