numOutChannels is (value) but the usacElementType sequence contains (value) channels
ISO IEC 23003-3 (USAC):numOutChannels: "numOutChannels shall be equal to or smaller than the accumulated sum of all channels contained in the bitstream"
ISO IEC 23003-3:
Fix the encoder to fill numOutChannels with the correct count of channels computed from the usacElementType sequence, then reencode the content.