I was debugging unrelated issue and noticed these lines in the log:
2020-08-03T19:07:15.167Z mediasoup:Channel [pid:117] RTC::RTCP::XR::Parse() | unknown RTCP XR block type [blockType:42]
2020-08-03T19:07:15.808Z mediasoup:Channel [pid:117] RTC::RTCP::XR::Parse() | unknown RTCP XR block type [blockType:42]
2020-08-03T19:07:16.949Z mediasoup:Channel [pid:117] RTC::RTCP::XR::Parse() | unknown RTCP XR block type [blockType:42]
2020-08-03T19:07:17.919Z mediasoup:Channel [pid:117] RTC::RTCP::XR::Parse() | unknown RTCP XR block type [blockType:42]
2020-08-03T19:07:18.785Z mediasoup:Channel [pid:117] RTC::RTCP::XR::Parse() | unknown RTCP XR block type [blockType:42]
2020-08-03T19:07:19.402Z mediasoup:Channel [pid:117] RTC::RTCP::XR::Parse() | unknown RTCP XR block type [blockType:42]
2020-08-03T19:07:20.261Z mediasoup:Channel [pid:117] RTC::RTCP::XR::Parse() | unknown RTCP XR block type [blockType:42]
2020-08-03T19:07:20.892Z mediasoup:Channel [pid:117] RTC::RTCP::XR::Parse() | unknown RTCP XR block type [blockType:42]
2020-08-03T19:07:21.507Z mediasoup:Channel [pid:117] RTC::RTCP::XR::Parse() | unknown RTCP XR block type [blockType:42]
Is this a problem?
It happens with screen sharing in Chrome using VP8.