Demystifying Spring 2014 updates for Office Web Apps Server 2013

As you might know, when Microsoft originally released Service Pack 1 (SP1) for Office Web Apps Server 2013 in April 2014, we discovered a flaw which prevents any public or cumulative updates from being installed.

Because of this flaw, we immediately removed the ability to download the service pack so we could repair it.  More on that here...

Once the regression was patched, we published a new KB with the patched version of SP1.  That KB can be found here...

If your Office Web Apps server is running on the regressed version of SP1, it is highly recommended you remove it and install the patched version.

The patched version of SP1 is build 15.0.4571.1502.

You can find the build number of your Office Web Apps server in Control Panel > Programs and Features

If you are on an older build than this, it means you are using the regressed version of SP1, or you are on an older Cumulative Update (CU), or an older Public Update (PU), or on the default release (RTM) build.  In any situation, it is highly recommended that you upgrade to at least SP1.


There is also the situation of the PUs & CUs which have been released since the patched version of SP1 was released.  Here are the major points to keep in mind. Download links at the bottom of this section.

-If you have the regressed version of SP1 for Office Web Apps server installed, please reference Jason Haak's blog on how to how to remove the regressed version of SP1, install the patched version of SP1, and install April PU.

-Since the June CU is right around the corner, the upgrade path MUST be done in the following order to be completely current with updates.  Patched SP1 > April PU > May PU > June CU.

-Generally when updating Office Web Apps Server, you can install the latest PU and CU, as each PU and CU are roll-ups of all other PUs and CUs before it.  However, in this unique situation, because of the regression with SP1, April PU must be installed before the latest available PU.

SP1 Regressed -

SP1 Patched - 15.0.4571.1502 -

April PU - 15.0.4605.1001 -

May PU - 15.0.4615.1001 -

June CU -

Latest available SP, CU, and PU for all Office/Office related products -


As always, please do not use automatic updates to install updates to Office Web Apps Server 2013.

Please follow the best practices outlined in the following TechNet article.

Edited 6/11: Updated April PU link.  Updated June CU link.

Comments (14)

  1. Anonymous says:

    Dan, apologies for the delayed response on our side.

    Any updates to the language packs will be rolled in to the CUs.

  2. Anonymous says:

    Thank You .. if our server is running the regressed version of SP1 and taking into account the article you refer to for removing this version, should the path (after uninstall of OWA) to update be

    * reinstall OWA
    * apply December 2013 CU (2850013)
    * install security patch (2878219)
    then continuing from this article
    SP1 (Patched)
    April PU
    May PU
    June CU

    Apologies in that I was a bit confused in terms of removing the regressed version of SP1 … regards.

  3. Anonymous says:

    thank you

  4. Dan_IT says:

    Are updates for language packs included in the CUs?

  5. Deano says:

    If we are pre SP1(15.0.4569.1506), can we progress straight to the install the latest CU? Or do we need to follow that same recommended upgrade path (SP1 -> Apr PU -> May PU -> August CU)? Hope that made sense … cheers.

  6. Peter says:

    What is the regressed version number?!

  7. Peter says:

    I have 15.0.4517.1003 installed. Why is it so hard to find updates for OWA?

  8. Peter says:

    And what’s the difference between the September 2014 PU and the September 2014 CU?! Plus, when I click on those links, there doesn’t seem to be downloads for OWA?

  9. Peter says:

    If you have regressed SP1, seems you don’t need to follow Jasaon Haak’s advice and uninstall OWA completely. I just did the remove in PowerShell and installed the proper SP1.

  10. Peter says:

    To answer my previous questions, you need to refer to Stefan’s blog – no September release for OWA. And the August one looks particularly dodgy (not a full CU WTF?). So I’m just going to install July’s one now.

  11. Lozerama says:

    Microsoft, why are you doing this to us?

  12. Lozerama says:

    Can we still use Microsoft Update for the non-OWA related updates to the Windows server?

  13. Dan Myhre says:

    One thing to note: MSFT still has the bad version of SP1 published as the slipstreamed version available for download on the licensing service center site. DO NOT USE. Download the RTM instead and apply the correct patches as noted in this blog.

  14. Entringer says:

    Hi, thanks you for this great post.
    For a fresh install of WAC 2013 could you confirm what should / must be installed :
    SP1 Release / PU April 2014 / PU May 2015 / last CU, Last Security Update.

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