How to fix:

Run the following command [under SharePoint bin folder] in each SharePoint server in the farm:

c:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\14\BIN\ psconfig.exe -cmd upgrade -inplace b2b -force -cmd installcheck -noinstallcheck

After running cumulative updates this error shows up. Runing PSConfig as instructed fixed the problem.

The SharePoint Health Analyzer detected an error. Product / patch installation or server upgrade required. All required products must be installed on all servers in the farm, and all products should have the same patching and upgrade level across the farm. Upgrade is required on server SP. Without the upgrade, the server is not in a supported state. On server SP, once all required products and/or patches are installed, perform an upgrade by either running PSConfigUI.exe or by executing the command “PSConfig.exe -cmd upgrade -inplace b2b -force -cmd applicationcontent -install -cmd installfeatures”. If a former upgrade attempt has failed, you may need to resolve upgrade specific issues before attempting upgrade again. Refer to the upgrade status page (http://sp:1111/_admin/UpgradeStatus.aspx) for information about current and prior upgrade attempts, and to determine issues that may be preventing upgrade from succeeding. For more information about this rule, see “″.

cd %COMMONPROGRAMFILES%\Microsoft Shared\web server extensions\14\bin
psconfig.exe -cmd upgrade -inplace b2b -force -cmd installcheck -noinstallcheck 
PSConfig.exe -cmd upgrade -inplace b2b -force -cmd applicationcontent -install -cmd installfeatures