Dashboard control "Invalid Selection"

When editing my dashboard Controls I see an “Invalid Selection” error pop-up in Value Source and Source Column.

What does this error mean?

This exception will happen when the source chart/column from where the Value List retrieves its values has been either removed from the dashboard OR removed and added again into the dashboard, therefore breaking the link between Value List and Value Source.
To remedy the situation either add back in the chart to the dashboard and recreate the control in question (this will re-create the broken link) or if it has been added already simply recreate the control.