Hi guys I need your brain cells. When I execute the test testBasic | context process debugger printedString | context := [ 20 factorial ] asContext. process := Process forContext: context priority: Processor userInterruptPriority. debugger := Smalltalk tools debugger new process: process controller: nil context: context. debugger stack expand. self assert: debugger stack selectedIndex = 1. printedString := OpalCompiler isActive ifTrue: [ '[ 20 factorial ] in DebuggerTest>>testBasic'] ifFalse: [ '[...] in DebuggerTest>>testBasic' ]. self assert: debugger stack selectedItem printString = printedString. debugger send. debugger send. self assert: debugger code getText = (Integer>>#factorial) sourceCode. self assert: debugger stack selectedItem printString = 'SmallInteger(Integer)>>factorial'. two times my image (latest get totally unusable). I thought that may be the process should be terminated so I added process terminate But nothing changes. I tried to debug the code but not chance. I tried self halt after [ 20 factorial ] asContext. I tried to execute the beginning in a workspace and not as a test to eliminate problem. But again no chance. So did I miss something obvious? Stef