Users can't join online meetings in Lync Online

Let's assume that you want to troubleshoot issues that occur when users try to join a Microsoft Lync Online meeting by using Microsoft Lync 2010, Lync 2013, the Lync for Windows Store app, or Lync for Mac 2011. Before you start, ask yourself and any external users who are experiencing the issue the following questions:

• How many users does the problem affect?
• Are the users internal or external to your organization?
• Can the affected users reproduce the problem on a single computer or on multiple computers?

When you have the answers to these questions, see the following table to determine the kind of issue that you're dealing with. This table is provided to help scope the problem to a certain category. However, some categories may be outside the technical support boundaries of a Lync Online support engineer.

Read the table as in the following example:

Be aware that each column and each row are mutually exclusive. That is, the issue affects either a single user or multiple users, and the issue can be reproduced either on one computer or on multiple computers.

If you don't experience one of the symptoms that are listed in the following table, use the scoping table in the "Scope" section to narrow the problem to a specific kind of issue. Then, you can troubleshoot the issue by following the steps that are outlined here.

Troubleshooting Windows client issues

To resolve any client or computer issue, first make sure that the computer is up to date. The computer should have the latest operating system updates, audio and video drivers, and software application updates to make connecting to a Lync Online meeting a successful experience. To do this, follow these steps:

1. Run Windows Update, and then verify that all optional hardware updates are installed. Specifically, make sure that video, audio, and network drivers are up to date.
2. Run the Office 365 Desktop Setup Tool, and then verify that all the required updates are installed.
3. Uninstall and then reinstall Lync 2010 from the Microsoft Office 365 portal.

Now that the computer is up to date and meets all minimum system requirements, clear any cached credentials or certificates from previous logons:

1. Verify that the user has the correct certificates in Certificate Manager. To do this, follow these steps:
   1. Open Windows Certificate Manager. To do this, click Start, click Run, type certmgr.msc, and then click OK.
   2. Expand Personal, and then expand Certificates.
   3. Sort by the IssuedBy column, and then look for a certificate that is issued by Communications Server.
   4. Verify that the certificate is present and that it isn't expired.
   5. Delete the certificate, and then try to sign in to Lync Online. If you can't sign in to Lync Online, go to step 2.
2. Remove the user’s Lync Online credentials from the Windows Credential Manager. To do this, follow these steps:
   1. Click Start, click Control Panel, and then click Credential Manager.
   2. Locate the set of credentials that are used to connect to Lync Online.
   3. Expand the set of credentials, and then click Remove from Vault.
   4. Try to sign in to Lync Online, and then type the new set of credentials.

Lync Online falls back to "anonymous join" if it can't authenticate. As long as anonymous participants aren't explicitly blocked from joining the meeting, they should always be able to join the meeting.

Troubleshooting network issues

1. Verify that the computer is connected to the network. Determine whether the computer can access other websites.
2. Use the Lync Online Transport Reliability IP Probe (TRIPP) to verify that the network meets the requirements for connecting to Lync Online.
   
   For more information about how to use the TRIPP tool, see the "How to verify that all network requirements for Lync Online are met" section of the following article in the Microsoft Knowledge Base:
   
   
   2409256

   (http://support.microsoft.com/kb/2409256#VerifyNetworkRequirements)

   You can't connect to Lync Online, or certain features don't work, because an on-premises firewall blocks the connection
3. Use the instructions in Microsoft Knowledge Base article 2566790
   (http://support.microsoft.com/kb/2566790/ )
   to verify that the required DNS records for Lync Online are resolving correctly. If any of these records aren't resolving from an internal or external DNS server, this could affect how Lync Online federation interacts with external Lync organizations. Contact your IT Administrator or DNS host to resolve the following items:
   • _sip._tls.<domain>
   • _sipfederationtls._tcp.<domain>

Fixing OCSMEET file associations in Windows

1. Verify that Lync Online is the default program that is used to open .ocsmeet files. To do this, follow these steps:
   1. Click Start, click Control Panel, and then click Default Programs.
   2. Click Associate a file type or protocol with a program.
   3. Scroll down to .ocsmeet, and then verify that Microsoft Lync 2010 is selected as the Current Default option.
2. If step 1 doesn't resolve the issue, uninstall and then reinstall Lync 2010 from the Office 365 portal.

Troubleshooting identity issues

This specific issue occurs when two users of the same Office 365 organization share the same user name (alias). Because of how Lync generates meeting URLs, two users on the same Office 365 organization who have the same user name will share the same meeting URLs. This causes the Lync Online conference to become corrupted.

To resolve this issue, change the user name of one of the users who has the duplicate user name. For information about how to edit and change user accounts in Office 365, see the following Help topic:

Troubleshooting Lync federation issues

If external users (and only external users) can't join a Lync Online meeting, first determine whether they're trying to join as authenticated users or as anonymous users.

• If the user is trying to join as an authenticated user from another Lync or OCS organization:
  • Your Lync Online organization must have External Communications enabled, and external communication must be completely open. Or, the external user’s domain must be in the Allow list.
    
    For help in enabling and troubleshooting domain federation, watch the following Microsoft Showcase video:
    Troubleshooting Lync Online public IM connectivity in Office 365 for Enterprises

    (http://www.microsoft.com/showcase/en/US/details/b34fb8bb-5fcb-4709-bec8-2a54840f6a10)
  • The external organization must have federation configured correctly from their side, too.
  • For more information about federating with a Lync Online organization, go to the following Microsoft TechNet website: 
    Configuring Federation support for a Lync Online 2010 customer

    (http://technet.microsoft.com/en-us/library/hh202193.aspx)
• If the user is trying to join as an anonymous user from Lync Attendee, or if the Lync Web App or is dialing in to a Lync Online conference with an ACP access number:
  • For anonymous join to work, a specific DNS SRV record must be present in DNS. For more information, click the following article number to view the article in the Microsoft Knowledge Base:
    2693625

    (http://support.microsoft.com/kb/2693625/ )

    External users can’t join Lync Online conferences anonymously or as guests
  • For various methods of confirming your Lync Online DNS records, click the following article number to view the article in the Microsoft Knowledge Base:
    2566790

    (http://support.microsoft.com/kb/2566790/ )

    Troubleshooting Lync Online DNS configuration issues in Office 365

Joining meetings by using the Lync Web App

If these troubleshooting steps don't resolve the issue, and if joining the meeting immediately is a bigger concern, use the Lync Web App. Be aware that the Lync Web App doesn't include Voice over IP (VoIP) functionality. That means that participants can only view sharing sessions. To do this, follow these steps:

1. Copy the Join URL from the meeting invite, and then paste it into Internet Explorer. (Warning: Don't press Enter yet.)
2. Add "?sl=1" to the end of the URL, and then press Enter.
   
   Note You must have Silverlight installed to use the advanced features of the Lync Web App.