Something strange happened after I upgraded to Zope 2.7.2. If there was a run time error in my external method, it used to return the module and line number as part of the error message. Now it just returns an error description without the line information. Here's an example; Site Error An error was encountered while publishing this resource. Error Type: KeyError Error Value: 'P' Troubleshooting Suggestions * This resource may be trying to reference a nonexistent object or variable 'P'. * The URL may be incorrect. * The parameters passed to this resource may be incorrect. * A resource that this resource relies on may be encountering an error. For more detailed information about the error, please refer to the error log. If the error persists please contact the site maintainer. Thank you for your patience. I upgraded to Zope 2.7.3 in the hope that the line numbers would start working again but no luck. Is there an option that controls this? If not, is there a fix that will get the line numbers working again? Now that I think about it, it may be related to some changes I made trying to get the Wing debugger working with Zope. I'll follow up on that thought. If anyone has any insite to this problem, I'd appreciated it. Thanks, Joe Goldthwaite