Renaming a class raises an exception

handleClassRenamed: anAnnouncement
        | items selectedIndex |
        items := self messages
                collect: [ :rgMethod |
                        | interestedClassName interestedClass |
                        interestedClassName := anAnnouncement oldName.
                        interestedClass := anAnnouncement classRenamed.
                        rgMethod isMetaSide
                                ^^^^^^^^^^^^^^^^^
                                apparently rgMethod does not understand isMetaSide

                                ifTrue: [ interestedClassName := interestedClassName , ' class'.
                                        interestedClass := interestedClass classSide ].
                        rgMethod parentName = interestedClassName
                                ifTrue: [ (interestedClass >> rgMethod selector) asFullRingDefinition ]
                                ifFalse: [ rgMethod ] ].
        selectedIndex := messageList selectedIndex.
        self messages: items.
        self setSelectedIndex: selectedIndex

I do not get why this bug shows up now.

https://github.com/pharo-project/pharo/issues/3993

I have the impression that the code of the MessageBrowser is bogus.

Stef