[Troubleshooting] Skype for Business server Front-End service cannot start RRS feed

  • General discussion

  • We noticed multiple similar cases in our forums that the Skype for Business/Lync server Front-End service cannot start, for example:

    Lync Server 2013 Front-End service RTCSRV stuck at "starting"

    Skype for Business Front End Service Will not Start

    Lync Front-End Service Not Starting

    In this article, we will introduce some troubleshooting steps.



    Skype for Business Server Front-End service cannot start, the status is always “Starting”.

    Troubleshooting steps:


    This issue may be caused by various reasons. It is recommended to check the Event Logs first for more details. Here are some common scenarios. 

    Scenario 1:

    Windows Server 2012 checks for a higher level of trust for certificate authentication. If any certificate is in an incorrect store, the Front-End service would not start normally.

    Related logs as below will show up under “Event Viewer” -> “Applications and Services logs” -> “Lync Server” directory: “Network connectivity issues or an incorrectly configured certificate on the destination server”.


    In this case, please use the following Windows PowerShell command to find the problematic certificates on the local computer certificate store.

    Get-Childitem cert:\LocalMachine\root -Recurse | Where-Object {$_.Issuer -ne $_.Subject} | Format-List * | Out-File "c:\computer_filtered.txt"

    Based on the “FriendlyName” in the “c:\computer_filtered.txt”, review the certificate installation.

    After changing the certificate store, restart the server and check if the service works.


    Scenario 2:

    While installing update on the Skype for Business servers, if something fails or multiple servers are in different CU versions, it may cause that the Front-End service fails to start.

    In the Event Log, there may be error messages like this: “The database schema and the Enterprise Edition Server were updated by different installation packages.”.


    If this happens, please open the update installer to check the patch installation status.

    If something fails (as shown above), it needs to rerun the update installer. Please make sure that all components are installed successfully (as shown below), and then restart the server, check if the Front-End service can start.

    In addition, if there are multiple Front-End servers in your environment, please compare the component versions of each server.

    As of the November 2015 Cumulative Update (6.0.9319.102), simply run "Get-CsServerPatchVersion" to get versions (as shown below).

    If anything is inconsistent, update the component versions to the same, then restart the servers to see the result.

    • Edited by ForumFAQ Tuesday, January 15, 2019 8:50 AM
    Tuesday, January 15, 2019 8:31 AM

All replies

  • Scenario 3:

    As we know, start with Lync Server 2013, the architecture of the Enterprise Edition (EE) Front-End pools has changed to a distributed systems architecture. For a Front-End pool to remain in a working quorum state, the Front-End server services that are used to manage the pool’s quorum must not be under 85% of the pool’s capacity, or quorum state could be lost. The Front-End service would not start properly.

    The following message would appear in Event Viewer: “Server startup is being delayed because fabric pool manager is initializing.”


    For such error, execute the following command to reset the quorum state:

    Reset-CsPoolRegistrarState -PoolFqdn "pool.domain.com" -ResetType QuorumLossRecovery

    After running completely, check whether the Front-End service is back to normal.

    Scenario 4:

    If the Front-End server fails to connect to the Back-End database, the Front-End service cannot start. This is a related error message in Event Viewer: “Failed to connect to back-end database.  Skype for Business Server will continuously attempt to reconnect to the back-end.” 


    For this scenario, please monitor the state of the SQL Server, here are some actions:

    a. Check the network connection between SQL and the Front-End server by “Nslookup” and “Ping” commands.

    b. Check the running status of related services on the SQL Server (as shown below), ensure the SQL services are running smoothly.

    If some of the services do not run properly, check the "Log on" account/password, and the Event logs for further troubleshooting.

    c. Check the “Logins” accounts in the SQL database, make sure that Skype for business related user groups (CS*, RTC*) exist, as shown below:

    If any group is missing, run this command on the Front-End server to update the existing database:

    Install-CsDatabase -ConfiguredDatabases -SqlServerFqdn <sql.domain.com> -Update

    After the SQL services are all running, check the status of the Front-End service.


    Hope this helpful to you!

    If you are encountering a similar issue, try the above steps. If the issue persists after all these steps, feel free to post a question with all details to our forum (via clicking “Ask a question” at the top left of this page), we’ll look further into the issue and try our best to help you.

    Please click to vote if the post helps you. This can be beneficial to other community members reading the thread.

    • Edited by ForumFAQ Tuesday, January 15, 2019 8:47 AM
    Tuesday, January 15, 2019 8:35 AM
  • Hi

    I checked this C literal and I could not see any login created after I ran this command:

    Install-CsDatabase -ConfiguredDatabases -SqlServerFqdn server.domain.com -Update

    c. Check the “Logins” accounts in the SQL database, make sure that Skype for business related user groups (CS*, RTC*) exist, as shown below:

    I 've only see completed with error messages but this is not fixed

    Please could you check my post in the following URL


    Warm regards MeVs

    Thursday, April 2, 2020 7:22 AM
  • It was fixed with information posted in this URL:


    Warm regards MeVs

    • Edited by MeVs Thursday, April 9, 2020 1:58 AM
    Friday, April 3, 2020 6:02 AM
  • Well, that was I thought.

    After having done the above troubleshooting, I was monitoring this Front End service, and I observed that the state changed from "running" to "starting" on 5 occasions in the almost last two weeks.

    As I don't know what causes it, I checked the RTC logging SQL Server messages in file 'C: \ Program Files \ Microsoft SQL Server \ MSSQL13.RTC \ MSSQL \ Log \ ERRORLOG'.

    2020-04-11 20:45:42.72 Server      The SQL Server Network Interface library could not register the Service Principal Name (SPN) [ MSSQLSvc/Napoles.maintlatam.com:RTC ] for the SQL Server service.

    Windows return code: 0x200b, state: 15.

    Failure to register a SPN might cause integrated authentication to use NTLM instead of Kerberos.

    This is an informational message.

    Further action is only required if Kerberos authentication is required by authentication policies and if the SPN has not been manually registered.

    Coudl anyone tell me any good advice to fix this issue?

    Warm regards MeVs

    Wednesday, April 15, 2020 11:33 AM