2034469 - Can’t join meeting on Cisco Webex from Firefox Nightly/Firefox Beta after creating meeting room

Status: RESOLVED DUPLICATE of bug 2033783

(Core :: WebRTC, defect)

Description

[Ardelean Oana, Desktop Test Engineering [:oardelean]]

Attachment: Screenshot 2026-04-23 at 16.12.28.png

Notes

• Not reproducible on Chrome or Firefox 150.0.
• No changes were made to the network connection.

*Found in

• Beta 151.0b1-build2;

Affected versions

• Nightly 152.0a1;
• Beta 151.0b1-build2;

Tested platforms

• macOS 12;
• M1 macOS 11;

Affected platforms

• macOS 12;
• M1 macOS 11;

Steps to reproduce

1. Launch Firefox.
2. Login to Webex/Cisco - in this particular scenario the login was made via Google Account.
3. Create and Join a Cisco/Webex meeting from Firefox Nightly/Firefox Beta.

Expected result

• The user can join the meeting without any issues.

Actual result

• The user cannot join the meeting.

Regression range

• Will look for one ASAP.

Comment 1

[Andreas Pehrson [:pehrsons]]

Hi Oana, thanks for filing. My immediate suspicion here would be that this is a dupe of bug 2033783. Fix is coming in bug 2032610. Can you reproduce in Release? We pushed a mitigation through Nimbus yesterday that changed the media.peerconnection.dtls.version.max pref in Release to 771. Could you confirm if this helps in Beta/Nightly and/or whether setting it to 772 in Release 150 makes the problem appear there too?

Keeping open until we can verify.

Comment 2

[Ardelean Oana, Desktop Test Engineering [:oardelean]]

Hi Andreas!

Setting media.peerconnection.dtls.version.max to 771 seems to solve the issue.

We re-tested with a combination between different Firefox browsers, please see the results below:

• Firefox Nightly 152.0a1- Firefox Nightly 152.0a1 - with media.peerconnection.dtls.version.max set to 771 - does not reproduce. Both host and guest can join the call.
• Firefox Nightly 152.0a1- Firefox Beta 151.0b1 - with media.peerconnection.dtls.version.max set to 771 - does not reproduce. Both host and guest can join the call.
• Firefox Release 150.0- Firefox Release 150.0- with media.peerconnection.dtls.version.max set to 771 - does not reproduce. Both host and guest can join the call.
• Firefox Release 150.0 - Firefox Release 150.0 - with media.peerconnection.dtls.version.max set to 772 - reproducible on both ends, neither the host nor the guest user can join the meeting.

Please let us know if there’s anything else we can do to help investigate further, thank you.

Comment 3

[Andreas Pehrson [:pehrsons]]

Thank you Oana!