Problem with sharing Chrome-Tab in 2.4.6

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glu...@gmail.com

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Apr 14, 2022, 6:08:15 PMApr 14
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Hi,

i experienced a strange problem when sharing a Chrome-Tab. In most cases it works well, but when sharing a tab with some specific .pdf files, it fails. For the user who is sharing everything looks normal. But the other participants just see the "3 dots"

The problem is reproducible on my server.

I also tried to reproduce the problem on the demo-server https://demo.bigbluebutton.org/ - but here it works.

We used the latest Chrome-version 100.0.4896.88

Any ideas what could be wrong?
HOAI.pdf
Bildschirmaufnahme 2022-04-14 um 23.53.19.mov

Paulo Lanzarin

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Apr 14, 2022, 6:18:28 PMApr 14
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Could you please state which BBB version your server is running? Thanks.

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glu...@gmail.com

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Apr 22, 2022, 5:26:32 AMApr 22
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It's V 2.4.6

glu...@gmail.com

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Apr 25, 2022, 5:16:23 PMApr 25
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Any ideas how to troubleshoot this issue? Just tried to reinstall - same issue again

Paulo Lanzarin

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Apr 27, 2022, 8:16:45 AMApr 27
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Since you report that it doesn't happen in the demo server, it seems likely to be some sort of setup issue.
Although it's a bit weird it only happens with tabs.

Can you please:
  - paste the output of bbb-check
  - make sure you have a valid TURN/STUN server set up for your server
  - get the console logs of a viewer who can't see the screen
  - preferably, get a dump of chrome://webrtc-internals of that same viewer
    * that one may expose user IPs - redact them if necessary

glu...@gmail.com

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Apr 27, 2022, 4:27:30 PMApr 27
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Hi,

see attachments.

There is a working TURN/STUN server
bbb-conf.txt
console.log.txt
webrtc_internals_dump.txt

Paulo Lanzarin

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Apr 28, 2022, 1:17:03 PMApr 28
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Nothing obvious stands out since the internals dump is missing. It only states that there's not video being transferred,
although the audio track of the tab sharing seems to be working fine. Interesting.

Does it work if you share a tab without audio (unmark the audio sharing checkbox when choosing the tab)?

Paulo Lanzarin

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Apr 28, 2022, 1:17:36 PMApr 28
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Typo: internals dump is missing => internals dump is missing candidates*.

glu...@gmail.com

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May 2, 2022, 4:16:35 AMMay 2
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The problem occurs also, when I share a tab without audio

Video/Webcam was not activated when I created this dump.

What is really weird is, that the problem occurs only when sharing a tab AND with specific content. The problem can be reliably reproduced with the pdf file from my first post. With other pdf files sharing a tab works without problems. 

Any ideas what I could try to analyze / debug this issue? Are there any configuration parameters regarding screen / tab sharing which I could try to change?

Paulo Lanzarin

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May 4, 2022, 2:05:46 PMMay 4
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> Video/Webcam was not activated when I created this dump.

I was referring to screen sharing video as in media kind when I said that no video was transferred.


> What is really weird is, that the problem occurs only when sharing a tab AND with specific content. The problem can be reliably reproduced with the pdf file from my first post. With other pdf files sharing a tab works without problems.

That's the part that is boggling. A tab's content shouldn't generally have such an effect over screen sharing, theoretically, so this
isn't really making much sense tbh.

Which is the OS you're using and is the PDF open directly in a browser tab or via another web-based app (eg google docs)?
You attached the PDF so I'll try to reproduce this issue further, just need to know the aforementioned details.



glu...@gmail.com

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May 5, 2022, 9:50:45 AMMay 5
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The problem occurs with clients using Windows or Mac OS - so it seems to be independent of client OS

The pdf is opened directly in a browser tab

I could also give you access to a room on my server to be able to reproduce the problem. If you want to have it just send me a private message

glu...@gmail.com

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May 18, 2022, 6:03:36 PMMay 18
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does anyone have an idea what I could do to further analyze this issue?

Paulo Lanzarin

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May 18, 2022, 7:02:17 PMMay 18
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> I could also give you access to a room on my server to be able to reproduce the problem. If you want to have it just send me a private message

Pinged in pvt.

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