When screen sharing people see black screen

[Viren_Manek]

Hi,

I had Thinkpad laptop and was using additional monitor on and off without any issues and suddenly since 2-3 weeks, when I am trying to share my screen, people are just seeing black screen. This is with both option i,e. when using laptop alone and also with additional monitor. Note there were no issues earlier.

Last weekend, I got a new laptop which is MS Surface 3, and after installing all MS apps on this machine, I am having the same issue. This is without any additional monitors.

This is causing issues for me and my team and would appreciate quick resolution.

Thanks and Regards,

Viren

[#2]

Problem solved. And as already recommended.

I changed ISP from Dodo to Internode.

No more issues.

[#3]

I too have the same black screen when ONLY using home Huawei modem. At the office it works and when I use my mobile as a hotspot it also works.
My ISP is iprimus.. been 1 week now with no resolution.

[#4]

iPrimus and Dodo are both owned by Vocus Group. Therefore both brands may share the same equipment and configuration, and hence give the same problems.

[#5]

@Viren_Manek 

Thank you, for pursuing this issue. I've had this problem on and off, trying to share my screen in Teams. I've tried various ways to resolve the problem. I thought it may have something to do with the resolution of my screen - it has a very high resolution, being a Surface Pro. However, even lowering that didn't help.

I then came across this thread. I appreciate the methodical way that you went about it - until the issue was resolved (for you).  I am the admin for our organization and have just turned off "Insert Quality of Service (QoS) markers for real-time media traffic". I hope this will resolve my problem as well.

[#6]

I logged a case with Dodo on 28/5 & follow it up with them weekly. I have been advised they are aware of the issue & their escalation support team is working on a resolution with Microsoft and other ISPs also affected. No eta when it will be resolved sorry.

The only 'fix' is to change ISP which I can't do as I live in a rural area & Optus/Dodo/I-Primus etc are the only ones available. I just keep hot spotting my mobile when I need to share my screen & once the session has started reconnect to my home wifi which seems to keep the port opened & I can keep sharing. If I stop sharing the port closes & I have to go back through hotspotting phone.

[#7]

@Adriana_001 update overnight is that my issue has now been fixed - I can share my screen in Team while using the Huawei modem. I have no idea who and what was done. A bit concerning when I don't know what happened / what was done to resolve the issue.

[#8]

Just tested mine with real hope. Alas, I was disappointed. Still not working for me (Mid North Coast, NSW, Australia)

[#9]

@Viren_Manek @JulieKeena 

Unfortunately the turning off of "Insert Quality of Service (QoS) markers for real-time media traffic" in the Teams Admin Meeting settings did not do the trick for me. I also tried connecting through my mobile hotspot in case it had anything to do with restrictions on my work network - to no avail.

Interestingly, in the same meeting, with the same connection, a colleague can share their screen with me - no problem, but visa versa it doesn't work.

[#10]

I have the same problem here in a Telstra NBN Fiber connection. I don't think it is just ISP related, but it may be a combination of router and ISP. I have an ASUS router RT-AC88U. If I connect laptop directly to the NBN modem, I don't have the problem. Therefore it will point to the router. I have disabled everything that I though it may give issues, but it still the same problem. So no QoS, and basically disabled all the security features with no go. If I use a VPN it works. Everything points to the router. I need to test it with another router.
Findings \ Notes:
1. Black screen sharing when using Asus - Router --> Telstra NBN
2. Works fine when connected directly: Laptop -- > Telstra NBN (no Asus router between laptop and NBN)
3. It works when using wireless broadband to Telstra network.
3. It works when VPNing out
4. It works when both machines are in the same network, therefore no router between them.
5. It works with the Web client

[#11]

Hi all,
hope this might help:
we had more than 10 users had this issue over a month ago, turned-off "Insert Quality of Service (QoS) markers for real-time media traffic" in Teams admin settings fixed the issue for all initially. However, the problem re-occurred for 3 users used to have the problem and 1 new user a couple of weeks ago. We then turn-on "Insert Quality of Service (QoS) markers for real-time media traffic" on late 25th Jun, and turn-off the setting on 27th Jun early morning. it fixed the issue for those 4 users since. All our users do not have the issue since. The key here is not to change the setting immediately. Hope it work for you.

[#12]

Update 7th July - update overnight is that IPRIMUS has fixed the issue. They said many people had called with the same "Black Screen" issue when sharing your screen in MS Teams. They did not say exactly what they did.

[#13]

As for a suggestion of a mate of mine, I entered a registry key to disable QoS all together for Teams. My understanding has been that you have to deploy a GPO to enable QoS for Teams as per following article: https://docs.microsoft.com/en-us/microsoftteams/qos-in-teams-clients. But it looks like that Teams desktop client is getting its QoS policy from the server, by the setting "Meetings\Meetings Setting\Network\Insert Quality of Service (QoS) markers for real-time traffic". This is my opinion, since I have not found any information to back it up.
How I fix it:
1. I created the registry key "HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\QoS" and the following registry entries under it (this entries are in the article but with the QoS values):
Name: Application Name
Type: REG_SZ
Data: Teams.exe

Name: DSCP Value
Type: REG_SZ
Data: 0 (This is Zero to disable QoS)

Name: Local IP
Type: REG_SZ
Data: *

You need to reboot.
Apparently, Microsoft is coming up with a fix in August.

[#14]

@atlacatl Tried registry fix & did not resolve the issue. 

I have spoken to Dodo technicians & been advised they are aware of the issue (approx 5000 customers are affected). It has been escalated & they are working closely with other ISP's & Microsoft to get it fixed.

Received an SMS from Dodo 1/7 "Your MS Teams apps issue is still under investigation by the network team. We will get in touch with you as soon as we have further updates"

I will be ringing them again today or tomorrow & hopefully get a more recent update for us all

[#15]

Today I received a message from Dodo saying that "Our Network team made changes to fix your MS Teams App issues and should now be resolved. Please let us know if you still need help."

[#16]

@DarylHartwell I received the same SMS & can confirm it is now all resolved 

[#17]

Can I ask exactly what Dodo said the issue was? I have the same issue with Optus and it is like talking to a brick wall with their support, it appears their only solution is to reset the router which is frustrating to say the least.

[#18]

did you get anywhere with optus? they are denying its an optus nbn issue and are telling me to speak to microsoft.

[#19]

@WM1 My ISP IPrimus acknowledged it was there problem.  The way I managed that was when I was in my work office it worked, at home it did not work. Only difference was location.

[#20]

@WM1 No luck with Optus. They blamed my router. My only solution was to use the browser based version of teams when working from home and I had no issues.

[#21]

Ok, Optus are now escalating it to senior IT. Lets see what happens. It works fine in the browser, but the app shows black when sharing.