If you get "Load control template file /_controltemplates/TaxonomyPicker.ascx failed: Could not load type 'Microsoft.SharePoint.Portal.WebControls.TaxonomyPicker' from assembly…" error in your event logs on SharePoint 2010 server, then it's most likely caused by "corrupted" code in TaxonomyPicker.ascx file. To fix the problem:
- Go to <drive>:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\14\TEMPLATE\CONTROLTEMPLATES
- Backup TaxonomyPicker.ascx before making any changes to it, then open TaxonomyPicker.ascx file to edit
- Find the following line: <%@ Control className="TaxonomyPickerControl" Language="C#" Inherits="Microsoft.SharePoint.Portal.WebControls.TaxonomyPicker,Microsoft.SharePoint.Portal, Version=14.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" %>
- Replace ',' with ',', so the line looks like this
<%@ Control className="TaxonomyPickerControl" Language="C#" Inherits="Microsoft.SharePoint.Portal.WebControls.TaxonomyPicker,Microsoft.SharePoint.Portal, Version=14.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" %>
instead of
<%@ Control className="TaxonomyPickerControl" Language="C#" Inherits="Microsoft.SharePoint.Portal.WebControls.TaxonomyPicker,Microsoft.SharePoint.Portal,Version=14.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" %>