After updating the SharePoint Foundation 2010 Server of our company to SharePoint Server 2010 I got this error in the Event Viewer:
Load control template file /_controltemplates/TaxonomyPicker.ascx failed: Could not load type 'Microsoft.SharePoint.Portal.WebControls.TaxonomyPicker' from assembly 'Microsoft.SharePoint.Portal, Version=14.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c'.
I could solve this error by re-enabling the corresponding feature using this PowerShell script:
Add-PSSnapin Microsoft.SharePoint.PowerShell -ErrorAction SilentlyContinue
[System.Reflection.Assembly]::LoadFile($Env:CommonProgramFiles+"Microsoft SharedWeb Server Extensions14ISAPIMicrosoft.SharePoint.dll") | out-null
Get-SPWebApplication -IncludeCentralAdministration | get-spsite | foreach-object { enable-spfeature "73ef14b1-13a9-416b-a9b5-ececa2b0604c" -force -url $_.Url -Verbose }
Note: The first to lines of the script enable are “standard lines of code” for me. They enable SharePoint PowerShell support if you use the Script without “SharePoint 2010 Management Shell”.