The code has an assignment to a non-existent property of an object, and the object does not support expando properties. The compiler attempts to create an expando property, but the properties cannot be added to the object and so the property is discarded.

To correct this error

Use an object that supports expando properties.
Do not attempt to add expando properties to objects that do not support them.

To correct this error

See Also

Concepts

Other Resources