As any other update operation performed directly on the view (as opposed to on the base data collection on which that view depends, see C1.LiveLinq.LiveViewExtensions.AsUpdatable<T>), it is allowed only if the view is not read-only (see View.IsReadOnly).

Although read-only properties of a view cannot be modified directly in the view, they still reflect up-to-date values of the source, so the difference is often not critical, you can always modify corresponding property in the source, that will automatically change the property in the view.

Reference

ViewRowCollection Class
ViewRowCollection Members