CRP20116
El valor del campo ClaveUnidad debe ser "ACT".
In English The Concepto of a payment receipt has ClaveUnidad ACT.
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']/cfdi:Conceptos/cfdi:Concepto
Test
@ClaveUnidad = 'ACT'
Checked with CFDI 4.0