# Error: a=ssrc line with msid information not found

**URL:** <https://mediasoup.discourse.group/t/error-a-ssrc-line-with-msid-information-not-found/49>\
**Category:** mediasoup libraries\
**Created:** [June 1, 2019, 1:46pm UTC](https://mediasoup.discourse.group/t/error-a-ssrc-line-with-msid-information-not-found/49 "2019-06-01T13:46:43Z")\
**Posts on this page:** 11\
**Page:** 1

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**Author:** ![mkh](https://yyz2.discourse-cdn.com/free1/user_avatar/mediasoup.discourse.group/mkh/32/145_2.png) [@mkh](https://mediasoup.discourse.group/u/mkh)\
**Post date:** [June 1, 2019, 1:46pm UTC](https://mediasoup.discourse.group/t/error-a-ssrc-line-with-msid-information-not-found/49/1 "2019-06-01T13:46:44Z")

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I’m getting the error with Chrome \< 70 in the following scenario:  
`start mic > start webcam (video only) > stop mic > start mic > error`

As far as I don’t start webcam, starting/stopping the mic is working fine.

The same happens for webcam:  
`start webcam > start mic > stop webcam > start webcam > error`

![image](https://global.discourse-cdn.com/free1/uploads/mediasoup/original/1X/f9f76a616f510ebf1df82949a480d05de9608850.png)

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**Author:** ![ibc](https://yyz2.discourse-cdn.com/free1/user_avatar/mediasoup.discourse.group/ibc/32/1540_2.png) [@ibc](https://mediasoup.discourse.group/u/ibc)\
**Post date:** [June 1, 2019, 11:11pm UTC](https://mediasoup.discourse.group/t/error-a-ssrc-line-with-msid-information-not-found/49/2 "2019-06-01T23:11:56Z")

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Does it also happen in [v2demo.mediasoup.org](http://v2demo.mediasoup.org)?

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**Author:** ![mkh](https://yyz2.discourse-cdn.com/free1/user_avatar/mediasoup.discourse.group/mkh/32/145_2.png) [@mkh](https://mediasoup.discourse.group/u/mkh)\
**Post date:** [June 2, 2019, 12:58am UTC](https://mediasoup.discourse.group/t/error-a-ssrc-line-with-msid-information-not-found/49/3 "2019-06-02T00:58:43Z")

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> Does it also happen in [v2demo.mediasoup.org](http://v2demo.mediasoup.org/)?

No and it does not happen even in demo v3. Probably because the demo is using pause/resume for mic while I’m using produce/close.

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**Author:** ![ibc](https://yyz2.discourse-cdn.com/free1/user_avatar/mediasoup.discourse.group/ibc/32/1540_2.png) [@ibc](https://mediasoup.discourse.group/u/ibc)\
**Post date:** [June 2, 2019, 8:48pm UTC](https://mediasoup.discourse.group/t/error-a-ssrc-line-with-msid-information-not-found/49/4 "2019-06-02T20:48:58Z")

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It has been fixed in mediasoup-client 3.0.6. [Here](https://github.com/versatica/mediasoup-client/commit/1be196f13b0334a84ca9a58c4746dde477738941?ts=2) the commit.

Can you please test it? I’ve tested it in the v3 demo app, but just in case.

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**Author:** ![ibc](https://yyz2.discourse-cdn.com/free1/user_avatar/mediasoup.discourse.group/ibc/32/1540_2.png) [@ibc](https://mediasoup.discourse.group/u/ibc)\
**Post date:** [June 2, 2019, 9:13pm UTC](https://mediasoup.discourse.group/t/error-a-ssrc-line-with-msid-information-not-found/49/5 "2019-06-02T21:13:53Z")

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NOTE: The issue also happens in Safari 11 and 12 (stable and Tech Preview) if Unified-Plan is not enabled in menu “Develop” - “Experimental Features” - “WebRTC Unified-Plan”. But that’s a clear bug in Safari that eventually we’ll report.

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**Author:** ![mkh](https://yyz2.discourse-cdn.com/free1/user_avatar/mediasoup.discourse.group/mkh/32/145_2.png) [@mkh](https://mediasoup.discourse.group/u/mkh)\
**Post date:** [June 3, 2019, 1:36am UTC](https://mediasoup.discourse.group/t/error-a-ssrc-line-with-msid-information-not-found/49/6 "2019-06-03T01:36:26Z")

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Yes it works fine now.👌  
Thanks.

I’m just getting a warning, not sure if is related:

**Chrome55:** `mediasoup-client:WARN:Transport producer.close() failed:Error: track not found`  
**Chrome69:** `mediasoup-client:WARN:Transport producer.close() failed:Error: associated RTCRtpSender not found`

**Scenario:** start mic \> start webcam \> stop mic \> start mic \> stop mic \> stop webcam \> warning

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<div class="post-metadata">

**Author:** ![ibc](https://yyz2.discourse-cdn.com/free1/user_avatar/mediasoup.discourse.group/ibc/32/1540_2.png) [@ibc](https://mediasoup.discourse.group/u/ibc)\
**Post date:** [June 3, 2019, 11:25pm UTC](https://mediasoup.discourse.group/t/error-a-ssrc-line-with-msid-information-not-found/49/7 "2019-06-03T23:25:40Z")

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Yes, I’ve seen the “associated RTCRtpSender not found” error. I’ve confirmed that Chrome \< 70 does not behave correctly when it comes to use the sender/receiver API of WebRTC (let’s say: the “pre-transceiver” API). Honestly I cannot spend much more time on it and prefer to go fo transceiver and modern versions of the browsers.

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**Author:** ![ibc](https://yyz2.discourse-cdn.com/free1/user_avatar/mediasoup.discourse.group/ibc/32/1540_2.png) [@ibc](https://mediasoup.discourse.group/u/ibc)\
**Post date:** [June 3, 2019, 11:48pm UTC](https://mediasoup.discourse.group/t/error-a-ssrc-line-with-msid-information-not-found/49/8 "2019-06-03T23:48:07Z")

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Well, I’ve found the error. It’s fixed in mediasoup-client 3.0.7. Can you confirm, please?

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<div class="post-metadata">

**Author:** ![mkh](https://yyz2.discourse-cdn.com/free1/user_avatar/mediasoup.discourse.group/mkh/32/145_2.png) [@mkh](https://mediasoup.discourse.group/u/mkh)\
**Post date:** [June 4, 2019, 5:39am UTC](https://mediasoup.discourse.group/t/error-a-ssrc-line-with-msid-information-not-found/49/9 "2019-06-04T05:39:05Z")

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Yeah fixed 👍

And please reduce the minimum required length of the posts. It’s already 20 characters.

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**Author:** ![ibc](https://yyz2.discourse-cdn.com/free1/user_avatar/mediasoup.discourse.group/ibc/32/1540_2.png) [@ibc](https://mediasoup.discourse.group/u/ibc)\
**Post date:** [June 4, 2019, 8:24am UTC](https://mediasoup.discourse.group/t/error-a-ssrc-line-with-msid-information-not-found/49/10 "2019-06-04T08:24:26Z")

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Changed to 5 for post replies.

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<div class="post-metadata">

**Author:** ![ibc](https://yyz2.discourse-cdn.com/free1/user_avatar/mediasoup.discourse.group/ibc/32/1540_2.png) [@ibc](https://mediasoup.discourse.group/u/ibc)\
**Post date:** [December 2, 2019, 11:10pm UTC](https://mediasoup.discourse.group/t/error-a-ssrc-line-with-msid-information-not-found/49/11 "2019-12-02T23:10:47Z")

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