CRP20103
El valor del campo SubTotal debe ser cero "0".
In English A payment receipt has SubTotal 0.
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
mx:dec(@SubTotal) = 0
Checked with CFDI 4.0