Missing URI ID scheme identifier

Error FX-SCH-A-000728 Factur-X

Attribute '@schemeID' is required in this context.

Mandatory rule: As long as it is violated, the invoice is invalid and will be rejected by validators.
What is wrong

The schemeID attribute is missing from ram:URIID. The URI ID's identification scheme is therefore not specified.

What the rule means

The schemeID attribute identifies the scheme used to interpret the URI ID value.

Please identify the product end user's URI ID scheme

The ram:URIID entry is missing the attribute that identifies its scheme. Add the schemeID attribute.

What to do
  1. Locate ram:URIID in the product end user's electronic communication details.
  2. Add the schemeID attribute to the element.
  3. Generate the invoice again and validate it.
What it looks like
✗ Triggers the message 
<ram:URIUniversalCommunication>
  <ram:URIID>urn:example:one</ram:URIID>
</ram:URIUniversalCommunication>
✓ Correct 
<ram:URIUniversalCommunication>
  <ram:URIID schemeID="value">urn:example:one</ram:URIID>
</ram:URIUniversalCommunication>
Technical details

The check requires the schemeID attribute to be present on ram:URIID.

Where the rule applies

The rule applies to the schemeID attribute on ram:URIID in the product end user's electronic communication details.

Context (rule/@context)
/rsm:CrossIndustryInvoice/rsm:SupplyChainTradeTransaction/ram:ApplicableHeaderTradeAgreement/ ram:ProductEndUserTradeParty/ram:URIUniversalCommunication/ram:URIID
Test expression (assert/@test)
@schemeID