Kerbal Space Program

If you have several vessels in flight in a save file and when you re-launch the game (and a part/config file is missing) a pop-up dialog comes up saying "Vessel Loading Error".
Which seems fine whent here is only ONE vessel affected. But if you have multiple vessels affected the pop-up dialogs are generated for each vessel and the "OK" button is bugged. (see screenshots attached).
A null reference error occurs:
[EXC 10:40:32.280] NullReferenceException: Object reference not set to an instance of an object
PopupDialog.SpawnPopupDialog (.MultiOptionDialog dialog, Boolean persistAcrossScenes, .UISkinDef skin, Boolean isModal)
PopupDialog.SpawnPopupDialog (Vector2 anchorMin, Vector2 anchorMax, .MultiOptionDialog dialog, Boolean persistAcrossScenes, .UISkinDef skin, Boolean isModal)
PopupDialog.SpawnPopupDialog (Vector2 anchorMin, Vector2 anchorMax, System.String title, System.String message, System.String buttonMessage, Boolean persistAcrossScenes, .UISkinDef skin, Boolean isModal)
ProtoVessel.Load (.FlightState st)
FlightState.Load ()
Game.Load ()
SpaceCenterMain+<Start>c__IteratorA3.MoveNext ()

Once you click ok, I also noticed that not all the kerbals then appear as missing (see screenshots attached).
First noticed this with mods and missing mod installs/parts.
But can easily be recreated with just stock and renaming/removing a stock config/part.

Logs and screenshots attached.
To Re-produce launch several vessels with same parts.. Close KSP. Rename/remove the config file for one or more of the parts on the launched vessels.
Re-launch KSP and observe.