Code 1120

Category: Screen share

Message shown in BigBlueButton

Code {errorCode}. Try sharing the screen again.

What it means

Screen sharing could not start after the maximum number of connection attempts.

Likely causes

UDP blocked between browser and server
Restrictive network or firewall
Server-side media configuration problem

What to do

First, check who is affected.

Only one or a few users: most likely a problem on the user's side, so follow the Student and Teacher steps.
Everyone in one room: check that room/meeting (settings, meeting ended or recreated, room limits).
Everyone in every room: most likely a server problem, so go to the Admin/server steps.

Students

Click Share screen again. Try another network (for example a mobile hotspot) to check whether your current network blocks the connection.

Teachers

If it repeats, share from another browser or computer. Stop sharing and start screen sharing again.

Server admins

Open UDP 16384–32768 on the server firewall and test it with netcat as in the firewall guide. Set up a TURN server (coturn) and list it in /etc/bigbluebutton/turn-stun-servers.xml for users on restrictive networks. Check that mediasoup's announced IP(s) match the server's public IPv4/IPv6.

Screenshot (coming soon)

Upstream source

v3.0.x-release · bigbluebutton-html5/imports/api/screenshare/client/bridge/errors.js:29

Dataset ref: v3.0.x-release

Browser check: Coming soonChrome extension: Coming soon