In the attachment you could find one file – Admin.master.cs
. Please, replace Admin.master.cs
in your web site with the file from the attachment; it is located in ~/Sitefinity/Admin
folder. The reason for the exception is that in IMenuContainer was added a new property SelectedMenuItemText and for some reason you don’t have the latest Admin.master.cs
page that implements this interface.
Hope this helps.
the Telerik team