--- a/DebugView.st	Mon Oct 14 11:42:19 2019 +0200
+++ b/DebugView.st	Tue Oct 15 18:13:33 2019 +0200
@@ -2616,9 +2616,11 @@
     "/ Q: this is good for multi-screen apps (where an error should not happen),
     "/    but not for multi-user development, where the debugger is entered often.
     "/    What is a good solution to this dilemma ?
-    Screen allScreens do:[:aScreen |
-        aScreen ungrabPointer.
-        aScreen ungrabKeyboard.
+    Screen allScreens do:[:eachScreen |
+        eachScreen isOpen ifTrue:[
+            eachScreen ungrabPointer.
+            eachScreen ungrabKeyboard.
+        ].
     ].
 
     ("inspectedProcess suspendedContext isNil