If a BindingSource control exists in the designer and one (and only one) control uses it as its DataSource, setting the DataSource for that control to (None) deletes the BindingSource (removes it from the designer, along with all generated code). If more than one control references it as its DataSource, this behavior does not occur.

The BindingSource should not be deleted, but rather remain in place.

Thanks for opening the issue.

Interesting, though, that you experienced something different. I'm using 6.3.11; possibly a version difference?