The property or method invoked is not valid in this context. For example, you might have used the Edit or Update method against an rdoResultset that is not updatable.
To avoid this error, check the sequence of the operations you are attempting and make sure they are correct. One possible cause is that you are trying to set a column value on a column that is a meta data column (that is, a column generated from an rdoTable and not an rdoResultset).