Can't mute when a screenshare is happening.

[ara4n]

Steps to reproduce

1. Be in a conf of ~5 people
2. User starts a screenshare
3. I try to mute myself so i can cough
4. Console fills up with

groupCall.ts:479 Uncaught (in promise) TypeError: Cannot read properties of undefined (reading 'setAudioVideoMuted')
    at aJ.setMicrophoneMuted (groupCall.ts:479:37)
    at useGroupCall.ts:299:15
    at j (module.js:242:55)
    at HTMLDocument.se (module.js:395:78)
    at HTMLDocument.i (helpers.js:74:23)
15:08:34.986 

Outcome

What did you expect?

ability to mute during screenshares

Operating system

macOS

Browser information

Chrome 105.0.5195.102 (Official Build) (arm64)

URL for webapp

call.element.io

Will you send logs?

Yes

[dbkr]

I can't repro this, but this line is:

for (const call of this.calls) {
    call.localUsermediaFeed.setAudioVideoMuted(muted, null);
}

...so presumably you've somehow ended up with a call with no local usermedia feed, which could be a call that's still establishing. A null check is probably the right answer.