MissingMethodException when creating CommandBindings

Our program fails to open window which uses command bindings. Program works fine on dozens of computers but with one customers computers it throws MissingMethodException. Computers are with Windows 7 and .NET Framework installed.

So I made a simple testprogram where I only create command bindings.

CommandBindings = new List<CommandBinding>();
CommandBindings.Add(new CommandBinding(ApplicationCommands.SaveAs, SaveAs));
 ...

And it fails when creating bindings.

System.MissingMethodException: Method not found: VoidSystem.Windows.Input.CommandBinding..ctor(System.Windows.Input.ICommand,System.Windows.Input.ExecutedRoutedEventHandler).

This same testprogram works fine on all other computers.

Any ideas?