August 2025 hotfix update 6.0.9319.881 for Skype for Business Server 2015, Front End Server and Edge Server (KB5064959)

This hotfix update fixes several issues in Skype for Business Server 2015, Front End Server and Edge Server. The version number of this update is 6.0.9319.881.

Note Server-side conversation history in branch site deployments is no longer supported in the March 2016 cumulative update.

Feature introduced in this update

Improvements and fixes

This cumulative update also fixes the issues that were previously listed in the following Microsoft Knowledge Base articles:

How to install the update

To install the cumulative update for Skype for Business Server 2015, Front End Server and Edge Server, you must follow the steps that are described in Updates for Skype for Business Server 2015 (KB3061064).

Note The Cumulative Server Update Installer applies all updates for the appropriate server role in one operation.

Prerequisites

There are no prerequisites for installing this cumulative update.

Registry information

To use one of the cumulative updates in this package, you don't have to make any changes to the registry.

Restart requirement

You may have to restart the computer after you apply this cumulative update.

Update replacement information

This cumulative update replaces the August 2021 cumulative update 6.0.9319.619 for Skype for Business Server 2015, Front End Server and Edge Server (KB5005361).

Update package installation information

To apply this cumulative update, you must follow the steps that are described in Updates for Skype for Business Server 2015 (KB3061064) on computers that are running the following server roles:

  • Skype for Business Server 2015, Standard Edition server
  • Skype for Business Server 2015, Enterprise Edition - Front End Server
  • Skype for Business Server 2015, Edge Server

Removal information

Before you uninstall this cumulative update, you must first uninstall all cumulative updates of core components whose version number is 6.0.9319.55 or later before you uninstall the cumulative updates for Skype for Business Server 2015 (Front End server and Edge server) that are at 6.0.9319.55 or a later version. Otherwise, you won't be able to start the RTCSRV service.

To remove both cumulative updates, follow these steps.

Note We recommend that you see the instructions that are described in Updates for Skype for Business Server 2015 (KB3061064) when you remove both cumulative updates.

  1. Open Control Panel, and then select Program.

  2. Select Installed Updates.

  3. Uninstall all updates of core components that are of version 6.0.9319.55 or a later version:

    Press and hold (or right-click) Skype for Business Server 2015, Core Components (KB5005359) with version 6.0.9319.619. Then, select Uninstall.

    Press and hold (or right-click) Skype for Business Server 2015, Core Components (KB5003605) at version 6.0.9319.606. Then, select Uninstall.

    Press and hold (or right-click) Skype for Business Server 2015, Core Components (KB4594637) at version 6.0.9319.598. Then, select Uninstall.

    Press and hold (or right-click) Skype for Business Server 2015, Core Components (KB4564307) at version 6.0.9319.591. Then, select Uninstall

    Press and hold (or right-click) Skype for Business Server 2015, Core Components (KB4558384⁠)⁠** with version 6.0.9319.580. Then, select Uninstall.

    Press and hold (or right-click) Skype for Business Server 2015, Core Components (KB4518733⁠)⁠** with version 6.0.9319.562. Then, select Uninstall.

    Press and hold (or right-click) Skype for Business Server 2015, Core Components (KB4505400⁠)⁠** with version 6.0.9319.559. Then, select Uninstall.

    Press and hold (or right-click) Skype for Business Server 2015, Core Components (KB4487978⁠)⁠** with version 6.0.9319.548. Then, select Uninstall.

    Press and hold (or right-click) Skype for Business Server 2015, Core Components (KB4492303) with version 6.0.9319.544. Then, select Uninstall.

    Press and hold (or right-click) Skype for Business Server 2015, Core Components (KB4464354) with version 6.0.9319.537. Then, select Uninstall.

    Press and hold (or right-click) Skype for Business Server 2015, Core Components (KB4340903) with version 6.0.9319.534. Then, select Uninstall.

    Press and hold (or right-click) Skype for Business Server 2015, Core Components (KB4075225) with version 6.0.9319.516. Then, select Uninstall.

    Press and hold (or right-click) Skype for Business Server 2015, Core Components (KB4074705) with version 6.0.9319.514. Then, select Uninstall.

    Press and hold (or right-click) Skype for Business Server 2015, Core Components (KB4036311) with version 6.0.9319.510. Then, select Uninstall.

    Press and hold (or right-click) Skype for Business Server 2015, Core Components (KB4012620) with version 6.0.9319.281. Then, select Uninstall.

    Press and hold (or right-click) Skype for Business Server 2015, Core Components (KB3207502) with version 6.0.9319.277. Then, select Uninstall.

    Press and hold (or right-click) Skype for Business Server 2015, Core Components (KB3199088) with version 6.0.9319.272. Then, select Uninstall.

    Press and hold (or right-click) Skype for Business Server 2015, Core Components (KB3149226) version 6.0.9319.259. Then, select Uninstall.

    Press and hold (or right-click) Skype for Business Server 2015, Core Components (KB3134259) version 6.0.9319.235. Then, select Uninstall.

    Press and hold (or right-click) Skype for Business Server 2015, Core Components (KB3097644) version 6.0.9319.102. Then, select Uninstall.

    Press and hold (or right-click) Skype for Business Server 2015, Core Components (KB3090687) version 6.0.9319.72. Then, select Uninstall.

  4. Uninstall the updates for Skype for Business Server 2015 (Front End server and Edge server) that are of version 6.0.9319.55 or a later version:

    Press and hold (or right-click) Skype for Business Server 2015, Front End Server (KB5005361⁠)⁠** with version 6.0.9319.619. Then, select Uninstall.

    Press and hold (or right-click) Skype for Business Server 2015, Front End Server (KB4558385⁠)⁠** with version 6.0.9319.580. Then, select Uninstall.

    Press and hold (or right-click) Skype for Business Server 2015, Front End Server (KB4518735) with version 6.0.9319.562. Then, select Uninstall.

    Press and hold (or right-click) Skype for Business Server 2015, Front End Server (KB4505401) with version 6.0.9319.559. Then, select Uninstall.

    Press and hold (or right-click) Skype for Business Server 2015, Front End Server (KB4487979) with version 6.0.9319.548. Then, select Uninstall.

    Press and hold (or right-click) Skype for Business Server 2015, Front End Server (KB4464355) with version 6.0.9319.537. Then, select Uninstall.

    Press and hold (or right-click) Skype for Business Server 2015, Front End Server (KB4340904) with version 6.0.9319.534. Then, select Uninstall.

    Press and hold (or right-click) Skype for Business Server 2015, Front End Server (KB4086059) with version 6.0.9319.516. Then, select Uninstall.

    Press and hold (or right-click) Skype for Business Server 2015, Front End Server (KB4074701) with version 6.0.9319.514. Then, select Uninstall.

    Press and hold (or right-click) Skype for Business Server 2015, Front End Server (KB4036312) with version 6.0.9319.510. Then, select Uninstall.

    Press and hold (or right-click) Skype for Business Server 2015, Front End Server (KB4012621) with version 6.0.9319.281. Then, select Uninstall.

    Press and hold (or right-click) Skype for Business Server 2015, Front End Server (KB3207506) with version 6.0.9319.277. Then, select Uninstall.

    Press and hold (or right-click) Skype for Business Server 2015, Front End Server (KB3199093) with version 6.0.9319.272. Then, select Uninstall.

    Press and hold (or right-click) Skype for Business Server 2015, Front End Server (KB3149227) version 6.0.9319.259. Then, select Uninstall.

    Press and hold (or right-click) Skype for Business Server 2015, Front End Server (KB3134260) version 6.0.9319.235. Then, select Uninstall.

    Press and hold (or right-click) Skype for Business Server 2015, Front End Server (KB3097645) version 6.0.9319.102. Then, select Uninstall.

    Press and hold (or right-click) Skype for Business Server 2015, Front End Server (KB3061059) version 6.0.9319.72. Then, select Uninstall.

File information

The global version of this cumulative update uses a Microsoft Windows Installer package to install the cumulative update. The dates and the times for these files are listed in Coordinated Universal Time (UTC) in the following table. When you view the file information, the date is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time item in Control Panel.

After the update is installed, the global version of this update has the file attributes, or a later version of the file attributes, that are listed in the following table:

File name File version File size Date Time Platform
File_apiem.dll 6.0.9319.634 35,93,136 05-Jul-22 17:52 x64
File_busyoptions.am Not applicable 12,095 01-Apr-17 12:50 Not applicable
File_busyoptions.exe 6.0.9319.619 10,38,216 26-Jul-21 01:51 x86
File_busyoptionsperf.dll 6.0.9319.259 56,528 14-Jun-16 15:19 x64
File_datacollectionperf.dll 6.0.9319.102 58,584 28-Oct-15 19:43 x64
File_exumrouting.exe 6.0.9319.281 10,15,488 01-Apr-17 02:24 x86
File_gac_microsoft.rtc.server.webinfrastructure.dll 6.0.9319.591 38,03,008 02-Jul-20 00:24 x64
File_iimfilter.exe 6.0.9319.580 9,32,216 18-Apr-20 17:09 x86
File_inboundrouting.exe 6.0.9319.619 4,66,312 26-Jul-21 01:50 x86
File_inboundroutingnonaudioscript.xml Not applicable 3,142 02-Apr-19 05:08 Not applicable
File_inboundrulesengine.dll 6.0.9319.619 7,42,792 26-Jul-21 01:51 x86
File_instantur.exe 6.0.9319.235 33,02,584 24-Feb-16 07:21 x64
File_interclusterrouting.exe 6.0.9319.235 9,98,112 24-Feb-16 07:28 x86
File_lbrouting.am Not applicable 20,725 22-Jul-21 08:16 Not applicable
File_lbrouting.exe 6.0.9319.619 9,32,744 26-Jul-21 01:51 x86
File_microsoft.liveserver.dlexpansion.dll 6.0.9319.281 5,24,048 01-Apr-17 02:13 x86
File_microsoft.rtc.server.mcufactory.dll 6.0.9319.281 10,81,616 01-Apr-17 02:13 x86
File_microsoft.rtc.server.udcadapters.dll 6.0.9319.537 11,84,816 29-Oct-18 13:48 x86
File_microsoft.rtc.server.udcadapters.resources.dll.en_us 6.0.9319.259 31,552 14-Jun-16 15:25 Not applicable
File_outboundrouting.exe 6.0.9319.634 11,35,520 05-Jul-22 17:53 x86
File_replicationapp.exe 6.0.9319.281 5,66,472 01-Apr-17 02:17 x86
File_routing.am Not applicable 20,096 01-Apr-17 12:50 Not applicable
File_rtcabattributeindexrules.xml Not applicable 40,292 23-Oct-15 22:45 Not applicable
File_rtcdbsyncagent.dll 6.0.9319.510 3,78,552 10-Nov-17 19:07 x86
File_rtcmrdrv64.sys 6.0.9319.289 2,44,992 05-Mar-21 09:57 x64
File_serveragent.dll 6.0.9319.634 11,09,408 05-Jul-22 17:53 x86
File_server_ 15.1.544.14 10,51,696 29-Oct-18 13:48 Not applicable
File_server_microsoft.rtc.internal.storage.lyss.dll 6.0.9319.881 8,68,424 08-Aug-25 00:55 x86
File_server_rtcaggregate.exe 6.0.9319.235 2,97,152 24-Feb-16 07:28 x86
File_server_rtchost.exe 6.0.9319.534 3,82,600 19-Jun-18 12:24 x86
File_server_rtcsrv.exe 6.0.9319.534 8,33,680 19-Jun-18 12:23 x64
File_sharedlineappearance.am Not applicable 18,752 23-Oct-15 22:46 Not applicable
File_sharedlineappearance.exe 6.0.9319.559 10,25,616 21-Jul-19 11:48 x86
File_sharedlineappearance.exe.config Not applicable 402 23-Oct-15 22:46 Not applicable
File_sipstack.dll 6.0.9319.634 60,53,792 05-Jul-22 17:52 x64
File_slaperf.dll 6.0.9319.235 56,496 24-Feb-16 07:21 x64
File_translationservice.am Not applicable 11,980 12-Jun-15 00:25 Not applicable
File_udcagent.am Not applicable 12,797 19-May-16 01:15 Not applicable
File_udcagent.exe 6.0.9319.548 10,77,296 08-Apr-19 10:28 x86
File_wrtces.dll 6.0.9319.634 1,11,77,880 05-Jul-22 17:53 x64

References

Learn about the standard terminology that Microsoft uses to describe software updates.

Get the latest cumulative update for Skype for Business Server 2015.