A common error message reported when installing a SharePoint CU is the following: "The expected version of the product was not found on the system".

You obviously will see this error if you try to install a SharePoint CU on a box where not SharePoint has been installed, but there is another reason why this problem can occur: if one of the components installed with SharePoint 2010, which should be upgraded by the CU, is on a patch level below the supported baseline of the CU.

Sounds complicated? It is not. Let me give you an example:

A SharePoint Server CU includes fixes for SharePoint Foundation and SharePoint Server and also for all available Language Packs for SharePoint Foundation and SharePoint Server (that's the reason why the package is so big). In a usual environment only a small number of language packs is installed. Often only one. You think your SharePoint Server does not have any language packs installed? You are wrong! If you install SharePoint Server 2010 English edition, then you have indeed the language independent SharePoint Server 2010 installed plus the English language pack.

With other words: even the simplest installation of SharePoint Server 2010 has 4 components installed. Lets assume you installed SharePoint Server 2010 English edition:

  • SharePoint Foundation 2010
  • SharePoint Server 2010
  • SharePoint Foundation 2010 English Language Pack
  • SharePoint Server 2010 English Language Pack

Plus the following components for any additional SharePoint Server language Pack (e.g. German):

  • SharePoint Foundation 2010 German Language Pack
  • SharePoint Server 2010 German Language Pack

If you are installing a service pack for SharePoint you need to ensure that all these four products are upgraded to the new service pack level.

For Service Packs it is similar. The SharePoint Server 2010 Service Pack English edition contains the service pack for the following 4 components:

  • SharePoint Foundation 2010
  • SharePoint Server 2010
  • SharePoint Foundation 2010 English Language Pack
  • SharePoint Server 2010 English Language Pack

That means unlike CUs you have to install the service pack for each additional language pack

Common error I have seen when upgrading to a new service pack level are the following:

  • The wrong service pack has been chosen. E.g. you installed SharePoint Server 2010 English edition but applied service pack for a different language. In such a situation only the language independent components are upgraded to the service pack but not the primary language pack. You will not get a warning or error on this as the service pack upgrades all components it finds on the system which match the service pack package.
  • Service Pack for SharePoint foundation has been installed but not for SharePoint Server. In such a situation only the SharePoint foundation components is upgraded but not the SharePoint Server component.
  • Same as above for a language pack. Then only the SharePoint foundation component of the language pack is upgraded but not the SharePoint server component of the language pack.
  • For some of the language packs no Service Pack has been installed

Each of the above listed errors will lead to inconsistent patch levels on the affected SharePoint server.

As SharePoint CUs can be installed on the latest and also for 12 months after release of a new service pack on the previous service pack to allow customers to evaluate the service pack thoroughly you might not notice that there is such an inconsistency as CUs install fine on such a system. But suddenly, 12 months later, CUs fail to install with the error message in the title. Why? Because the patch level of one of the installed components is below the supported level.

How can you detect such problems?

There are different methods:

  • Check the list of installed service packs in Control Panel
  • Go to the Central admin site and check the patch status using the "Manage Patch Status" page
  • Finally, if the above listed steps do not help you to identify the problem, you can use the tool Roiscan which generates a detailed report of all installed Office components, including SharePoint, and verify the patch level of each components.