warningXRechnung 3.0.2 (Germany)profileCII
This CII file might use the concept of Sub Invoice Lines. However XRechnung does not support this.
The CII document appears to use sub invoice lines, which plain XRechnung does not support.
Flatten the sub-lines into ordinary invoice lines, or send the document against the XRechnung EXTENSION profile rather than the core one.
CII — context —
not(exists(//ram:ParentLineID))
Nothing is stored, and the whole invoice is checked, not just this rule. A PDF only works if it is Factur-X / ZUGFeRD — a PDF with the invoice XML inside it.