Hi I tried to load the following code into 10082 and 10083 in 10082 it works like a charm, in 10083 loadOB "self loadOB" | instClass | instClass := self environment at: #Installer ifAbsent: [self new installingInstaller]. instClass ss project: 'AST'; install: 'AST-lr.158'. instClass ss project: 'RefactoringEngine'; install: 'RefactoringEngine-ab.51'. instClass wiresong project: 'ob'; install: 'OmniBrowser-dr.418'; install: 'OB-Standard-dr.353'; install: 'OB-Morphic-dr.56'; install: 'OB-Enhancements-dr.216'; install: 'OB-Refactory-lr.100'; install: 'OB-SUnitIntegration-dc.9'. I get a extremely strange bug UndefinedObject DNU value: !!!!! when Instance := nil is selected and RefactoryChangeManager class>>nuke Instance notNil ifTrue: [Instance release]. Instance := nil RefactoryChangeManager class >>initialize self nuke. UndoSize := 5