When submitted a change on a TV series via the contribution form, you may be presented with the error "No Existing Data".

This means that the data you are trying to update does not exist on the series-level page.
Please be aware that the item is stored on the individual episode pages but populates the series page to provide a more complete overview.
To update this data type, please use the yellow Edit Page or any of the Edit pencil icons on the episode page that the item is located on.