Christoph Thiede uploaded a new version of Morphic to project The Trunk:
http://source.squeak.org/trunk/Morphic-ct.2054.mcz

==================== Summary ====================

Name: Morphic-ct.2054
Author: ct
Time: 25 November 2022, 6:03:40.232495 pm
UUID: 50a95075-43f1-024e-ba2f-c74863e21f26
Ancestors: Morphic-mt.2053

Fixes dangling keyboard focus for children of deleted morphs.

Thanks to Robert (rhi) for the original bug report and to Marcel (mt) for the solution!

=============== Diff against Morphic-mt.2053 ===============

Item was changed:
  ----- Method: HandMorph>>releaseKeyboardFocus: (in category 'focus handling') -----
  releaseKeyboardFocus: aMorph
  	"If the given morph had the keyboard focus before, release it"
  	self keyboardFocus == aMorph keyboardFocusDelegate
+ 		ifTrue: [self releaseKeyboardFocus].
+ 	
+ 	"Also release the keyboard focus for any child of aMorph."
+ 	self keyboardFocus ifNotNil: [:focus |
+ 		"like #hasOwner:, but identity instead of equality comparison"
+ 		focus allOwnersDo: [:m | 
+ 			m == aMorph ifTrue: [
+ 				^ self releaseKeyboardFocus]]].!
- 		ifTrue:[self releaseKeyboardFocus].!