Find the error if I used Execute, Display, or Inspect
If the Script Debugger opens after you use the Edit menu options Execute, Display, or Inspect, do the following: 
1.	Look at the message stack (middle-left pane). 
2.	Find the lowest ExceptionalEvent>>#signalWith: message. (It's close to the top of the stack.) 
3.	Find the message UndefinedObject>>#Doit. It's just below the lowest ExceptionalEvent>>#signalWith: message. 
4.	Click on the message that's between ExceptionalEvent>>#signalWith: and UndefinedObject>>#Doit. It should contain the code that caused the error. 
Last modified date: 08/09/2019