SharePoint 2010: Event ID 7043: Could not load type 'Microsoft.SharePoint.Portal.WebControls.TaxonomyPicker'

Problem

Reviewing the Windows Application event log, one day, I found the following:

Log Name	Application
Source	Microsoft-sharePoint Products-Sharepoint Foundation
Date	[date]
Event ID	7043
Task category	Web Controls
Level	Error
Keywords
User	[SharePoint service account]
Computer	[SharePoint host]
Description Load control template file /_controltemplates/Taxonomypicker.ascx failed: could not load type 'Microsoft.sharepoint.portal.webControls.Taxonomypicker' from assembly... For more information...

The machine on which this event occurred was the host for a newly installed SharePoint 2010 instance.

Solution

1. Temporary solution
   1. Open a folder and browse to: C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\14\TEMPLATE\CONTROLTEMPLATES\
   2. Open the file TaxonomyPicker.ascx in a text editor.
   3. Search for the string: ","
   4. Replace it with just a comma and a space: ,
   5. Save the file.
   6. Reset IIS.
   7. Perform these steps on each farm server (except the database server).
2. Permanent solution
   1. Delete this file from the controls folder (see above).

References

• Microsoft Knowledgebase article KB2481844.
• Richard Wilson's Blog: SharePoint 2010, Event ID 7043: Could not load type 'Microsoft.SharePoint.Portal.WebControls.TaxonomyPicker'.

Notes

• The problem involved a control template that remained in the control template folder but that had been removed from the code base. In other words, this was a release error by Microsoft. A temporary solution was to fix a minor typo in this control, as discussed in KB2481844. However, the error will re-appear after a system restart, even though the typo no longer exists. The permanent solution was to remove the control completely.
• Renaming the control simply leads to the new problem of a (renamed) control being loaded for which no code exists in the code base.