This counter tracks frames with a compressed IP header that encountered an error while decompressing (rebuilding) the full IP header. This isolates a header-compression protocol failure -- likely a state desynchronization between the compressing transmitter and this decompressing receiver -- from payload-level or RF-level errors, since the frame's actual data may be intact while only the header reconstruction failed. If the transmit side resets its header-compression context, for example after a brief outage, without this receiver doing the same, a burst of these errors would appear until both ends' compression state realigns.