CRP20111

Solo debe existir un Concepto en el CFDI.

In English A payment receipt has exactly one Concepto.

error: the document is invalid

What the rule checks

As the rule set's publisher wrote it. The rule runs on every element the context matches, and fails where the test is false; the validator reports the line of that element.

Context
/cfdi:Comprobante[@TipoDeComprobante = 'P' or cfdi:Complemento/pago20:Pagos]
Test
count(cfdi:Conceptos/cfdi:Concepto) = 1

Checked with CFDI 4.0