And I am back with new problems with pharo 5 , I hope you missed me :D If I try to create a new class called ChrTimeInputM that subclasses TextMorph I am getting this MNU with the stack bellow I tried to replace includesKey: with includesClass: but then it alerts me falsely that there is already an existing class in the image, I tried this on the latest pharo 5 image with nothing installed in it. Here is the stack RBBrowserEnvironment(Object)>>doesNotUnderstand: #includesKey: PackageTreeNautilusUI(AbstractTool)>>compileANewClassFrom:notifying:startingFrom: PackageTreeNautilusUI(AbstractNautilusUI)>>compileAClassFrom:notifying: ClassDefinitionAcceptor>>accept:notifying: PackageTreeNautilusUI(NautilusUI)>>compileSource:notifying: PackageTreeNautilusUI(AbstractNautilusUI)>>whenTextAcceptedInView: MessageSend>>value: MessageSend>>cull: MessageSend>>cull:cull: [ action cull: anAnnouncement cull: announcer ] in AnnouncementSubscription>>deliver: in Block: [ action cull: anAnnouncement cull: announcer ] BlockClosure>>on:do: BlockClosure>>on:fork: AnnouncementSubscription>>deliver: [ subscription deliver: anAnnouncement ] in SubscriptionRegistry>>deliver:to:startingAt: in Block: [ subscription deliver: anAnnouncement ] BlockClosure>>ifCurtailed: SubscriptionRegistry>>deliver:to:startingAt: SubscriptionRegistry>>deliver:to: SubscriptionRegistry>>deliver: Announcer>>announce: RubScrolledTextMorph>>acceptContents RubScrolledTextMorph>>whenTextAcceptRequest: MessageSend>>value: MessageSend>>cull: MessageSend>>cull:cull: [ action cull: anAnnouncement cull: announcer ] in AnnouncementSubscription>>deliver: in Block: [ action cull: anAnnouncement cull: announcer ] BlockClosure>>on:do: BlockClosure>>on:fork: AnnouncementSubscription>>deliver: [ subscription deliver: anAnnouncement ] in SubscriptionRegistry>>deliver:to:startingAt: in Block: [ subscription deliver: anAnnouncement ] BlockClosure>>ifCurtailed: