The Control *control* has thrown an unhandled exception in the designer and has been disabled.
Cannot access a disposed object.
Object name: 'SplitterPanel'.
This error occurs when I place a custom control whose base is a UserControl inside a Panel/Tab Control etc on my form. It appears the order the controls are added to the form effect the exception being thrown.
If I add the UserControl and then the panel, then drag the UserControl onto the panel the exception doesn't get thrown. However if the Panel is already on the form before the UserControl is placed on the form, and then nested, the exception occurs whenever the designer re-intialises the designer pane, or the pane is closed.