Error Failed to execute 'createOffer' on 'RTCPeerConnection

Bug Report

Your environment

• Operating system: Catalina 10.15.7
• Browser version: chrome Version 87.0.4280.67 (Official Build) (x86_64)
• mediasoup version: 3.6.16
• mediasoup-client version: 3.6.12

Issue description

1. produce screen sharing with audio using getDisplayMedia.
2. close created producers.
3. produce screen sharing with audio again
4. then the error occurs and producing failed

Failed to produce DOMException: Failed to execute 'createOffer' on 'RTCPeerConnection': Session error code: ERROR_CONTENT. Session error description: Unknown transceiver.

• This error occures only when selecting chrome tab with share video.

• And It didn’t occur in chrome version 86.0.

[ibc]

Ok, confirmed that:

• This is a bug in libwebrtc/Chrome and not in mediasoup-client (even if easier to report everything to mediasoup project because we don’t request jsfiddles).
• The issue does not happen in Chrome 88 or 89 (Canary).
• According to the issue in libwebrtc they are gonna fix M87 soon.

So closing. Nothing to do in mediasoup-client side.

[ibc]

I don’t want to go to higher levels. The issue is clearly reproducible with my steps above and the error is in pc.setLocalDescription() (there may be more, but this is clear) so this is a regression in Chrome/libwebrtc.

I know that it’s easier to report issues here than in Chroimum/libwebrtc trackers since there they require a jsfiddle that reproduces the error and they don’t want to know anything about higher layers (such as mediasoup-client library). If I have time next week I’ll try to make a jsfiddle reproducing the bug by just using PeerConnections. If anyone can help on this, that would be great, but this is not a bug in mediasoup-client. I’ll keep this issue open for updates.