Random uses not able to present screens. RRS feed

  • Question

  • A small number (5 out of 600) are unable to share via Lync/Skype clients either being the presenter or viewing someone else's presentation. I recently upgraded from lync 2010 server to Skype for business 2015. That is when it started for these users. All other functions seem to work.  The error they receive is the generic "network issues are preventing the presentation"

    There are using various clients lync 2010 or 2013. The problem happens in both directions and with internal users and external clients we federate with.

    Since it isn't a global issue can't be some server/firewall configuration I have wrong. I am assuming the clients firewall should be correct since it worked before and their client has not changed only the server.  I could put in a rule to check but why not all the 100's of other clients?

    I obtained their login information, logged in with test boxes and had no issues so it is not the account itself.  The only real clue is that these users all work from home or at least only have the issue when they work from home but we have at least a 100 other work from home users without the issue.

    What would be some things to check when troubleshooting with them? 

    Monday, October 17, 2016 3:06 PM


  • We were able to track it down to firewall ports being blocked in the one office so that internal uses could not present desktops with external users.
    • Marked as answer by Craigbon Thursday, October 20, 2016 2:24 PM
    Thursday, October 20, 2016 2:24 PM

All replies

  • What tests did you perform?  If it worked with a test box, was that internal to internal only?  Could you do internal to external?  If you take a test box on the Internet, could you do external back to internal?

    How is your Edge server set up?  Are you using 3 external IPs for the edge with TCP/443 for each?  If you're using a single IP and 5061/444 or some other ports for the edge, it's possible their ISP or home router is blocking this.

    Please remember, if you see a post that helped you please click "Vote" on the left side of the response, and if it answered your question please click "Mark As Answer". SWC Unified Communications This forum post is based upon my personal experience and does not necessarily reflect the opinion or view of Microsoft, SWC, their employees, or other MVPs.

    Monday, October 17, 2016 7:05 PM
  • I am assuming this is internal Sharing of your presentation. One of the more important things to verify, when you move to Skype for Business, is to make sure you have legacy Clients removed from your environment. I would say you want to remove Lync 2010 and 2013 clients completely. The bits have changed on the client, and you are going to get yourself into an interoperability problem. There are bugs in various version of all Lync 2010 and 2013 clients.

    Believe me, I Have had many customers come to me, who go on for months ignoring this very small detail. If you want to get to 0 client issues, get your Server to the latest SFB 2016 CU and The Client to SFB and 2016 CU level.

    So Let me take a step back and say you could also have a network issue at the client side. You could have one bad switch and 5 clients are connected to the one bad hub. Second, you could have the five clients have something loaded on their clients that are causing the screen share to fail. This could be a freeware app, shopping coupon saver or something else. Finally, if you are sharing to 210 persons, persons 206-210 may not get the presentation, as you are at the limit of the maximum users in the Conference.

    However, My experience dictates, that at 6/500 presentation, you are setup properly and your not reporting 5 users, who sit next to each other as the issue. That being said, Your facing a client version issue. I have seen it since Skype for Business has come out.

    Take a look at the three clients and see what the requirements are. I think you will agree, the earlier versions of Lync are just not designed for the Skype for Business Era. Meanwhile, SFB Client, Is backward compatible, and will meet all your needs.



    Now finally, and possibly most compelling is the way PowerPoint Presentations were designed for Lync 2010 vs Skype for business. You can research and see that they are very different. If you have multiple versions of the client, spread across three versions, you may have combination, that just end up not being compatible, because of all the variables involved.

    To conclude, I am aware of certain bugs over time, that have resulted in the recommendation, to just get the organization up to the Skype client version, for all users, once you have updated to SFB. You will no longer have issues with these small groups of users.

    I hope this helps.

    Monday, October 17, 2016 11:45 PM
  • Well I re-read your Post and I did not address the fact that your users are at home. Ok this changes the dynamic. Next question do you use VPN? If you use VPN, and its not split tunneled, designed for Skype for Business, then you are likely to have failures for complex operations like screen sharing, and powerpoint presentations.

    What you do is direct all you employees, to log off of lync and Outlook, Disconnect the VPN, and then log into Lync or SFB, with the VPN stopped. You will now find there are no issues.

    The problem here is the Lync client or SFB client, will generally end up going down the VPN tunnel, and this causes a double encryption. This makes the signal so bad, that there is no way a Power Point will work.

    Technically, once Skype is logged in, and you are on the conference, you could possibly re-connect to the VPN. However, this is not 100%. Bottom Line is If your users are at home, and you want Power Point Presentations, you will need to kill the VPN, or Deploy a Split VPN tunnel.


    Monday, October 17, 2016 11:52 PM
  • Hi Craigbon,

    Welcome to our forum.

    In addition to above suggestions, we suggest you renew the certificate on the Edge server to check if the issue persist:


    Notice: this link also apply to SFB server 2015.

    If there are any questions or issues, please be free to let me know and we will pleasure to help you. If the above suggestions are helpful to you, please mark it as answer so that someone who has similar issue could find this thread as soon as possible.

    Best Regard,
    Jim Xu
    TechNet Community Support

    Please remember to mark the replies as an answers if they help and unmark them if they provide no help.
    If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com.

    Tuesday, October 18, 2016 3:13 AM
  • The certificate for the Skype edge box is only a month old so renewing it would not be possible.

    Actually of all the replies the one about the client version seems the best avenue for me. We do have a lot of lync 2010/2013 clients although this problem is not wide spread maybe I will upgrade the ones that have the issue with a newer version of client.

    As far as testing goes I have tested with one of the problem users crendentials in every direction you can think with my test boxes.  Internal and external with various clients 2010 to Skype and can't reproduce the issue myself. So it seems to be just on these users pc's. They are corporate equipment just used at their home.

    I do use a single IP instead of the 3 separate ones.

    No we do not use VPN. clients uses Citrix except for Skype but all other software is accessed remotely via a Citrix connection.

    Powerpoint presentations are not a issue since we use a Office Online Server aka Office web apps for this use.

    I am going to try a lync cleanup tool first then upgrade to new version and let you know the results.

    Tuesday, October 18, 2016 12:55 PM
  • Hey,

    Do you accidently have .netFramework 4.6.1 installed on your FrontEnd servers?

    If the workstations/laptops don't have the latest patches than this can cause an issue in sharing if you have .NetFrameWork 4.6.1 installed on your front-end. If you rollback to 4.5.2 this is solved.
    Or you need to make sure all latest patches have been deployed to the clients.



    Tuesday, October 18, 2016 1:34 PM
  • no but the reverse is true. Our users have .net 4.6.1 installed and the server only 4.5.2. But again this is a localized problem to a handful of home users never internal and they all have 4.6.1
    Tuesday, October 18, 2016 4:56 PM
  • Well this just got a lot odder. I tested with a client using lync 2013. We have 3 offices 2 small ones and one large office in Maryland. The large office in MD is where all the Skype servers are located Edge/Frontend/Office Online

    Presenting desktop/powerpoint works perfectly with external clients AND my small office in ohio. However it fails with internal clients in the Maryland office.  This is from a external corporate user to this main office.  I guess some odd firewall rule?  I can't think of anything else that would block this to only one office.

    let me try and get this clear in my head. When presenting desktop (let's take office online server out for the moment) The external user hits the Edge boxes and has IM session with Internal users. When sharing their desktop is this session handled by the front end box which just forwards the presentation to a internal user or is it actually on the users desktop itself.

    Wednesday, October 19, 2016 1:30 PM
  • Some more details on this odd issue. If you start by presenting Powerpoint slides thereby using our Office Online server then stop presenting that, but do not close the conservation window you can present your desktop without issue.  That works both ways external with home user to internal office and vice versa.

    If you start with sharing desktop it fails and switching to presenting powerpoint fails unless you delete the conversation window and start over.

    Wednesday, October 19, 2016 3:19 PM
  • We were able to track it down to firewall ports being blocked in the one office so that internal uses could not present desktops with external users.
    • Marked as answer by Craigbon Thursday, October 20, 2016 2:24 PM
    Thursday, October 20, 2016 2:24 PM