Hello,there i get a warn message

i install licode by Official’s site , and i run success and the demo is success, but the console output some message:
-381604350ff5] (rtp_utility.cc:342): Failed to find extension id: 1
[erizo-65d805f2-f297-b064-2327-381604350ff5] (rtp_utility.cc:342): Failed to find extension id: 1
[erizo-65d805f2-f297-b064-2327-381604350ff5] (rtp_utility.cc:342): Failed to find extension id: 1
[erizo-65d805f2-f297-b064-2327-381604350ff5] (rtp_utility.cc:342): Failed to find extension id: 1
[erizo-65d805f2-f297-b064-2327-381604350ff5] (rtp_utility.cc:342): Failed to find extension id: 1
[erizo-65d805f2-f297-b064-2327-381604350ff5] (rtp_utility.cc:342): Failed to find extension id: 1
[erizo-65d805f2-f297-b064-2327-381604350ff5] (rtp_utility.cc:342): Failed to find extension id: 1
[erizo-65d805f2-f297-b064-2327-381604350ff5] (rtp_utility.cc:342): Failed to find extension id: 1
[erizo-65d805f2-f297-b064-2327-381604350ff5] (rtp_utility.cc:342): Failed to find extension id: 1
[erizo-65d805f2-f297-b064-2327-381604350ff5] (rtp_utility.cc:342): Failed to find extension id: 1
[erizo-65d805f2-f297-b064-2327-381604350ff5] (rtp_utility.cc:342): Failed to find extension id: 1
[erizo-65d805f2-f297-b064-2327-381604350ff5] (rtp_utility.cc:342): Failed to find extension id: 1

what i can do?please help