int bodyStart = headerStart + Smb2Constants.SMB2_HEADER_LENGTH;
        // Error response structure: size(2)=9, errorContextCount(1), reserved(1), bc(4), errorData(bc)
        SMBUtil.writeInt2(9, buf, bodyStart);
        buf[bodyStart + 2] = 0x02; // errorContextCount
        buf[bodyStart + 3] = 0x00; // reserved
        int bc = 4;