Job ProgressBar logic is bogus here we have: progress ^ (currentValue - min) / (max - min) raises ZeroDivide. and progress is invoked by basicProgress: basicProgress: aNormalizedFloat "Set the progress: 0.0 - 1.0 without triggering an update" currentValue := (min + ((max - min) * aNormalizedFloat)) In my case I have currentValue, min and max = 1 does anybody know this code? and how we can fix it. How to reproduce the problem MCStReaderTest debug: #testCommentWithStyle Here we have fileInFrom: aStream | changes | changes := ChangeSet scanFile: aStream from: 0 to: aStream size. aStream close. ('Processing ', self packageName) displayProgressFrom: 1 ^^^^^ which set the min to 1. Setting it to 0 can solve the problem but the progress bar should be more robust to: changes size ^^^^^^^^^^ max to 1 during:[:bar| | chgRec | 1 to: changes size do:[:i| bar current: i. chgRec := changes at: i. self perform: (chgRec type copyWith: $:) asSymbol with: chgRec. ]. ]. Stef