When doing quick edits to our web.config files many of us are inclined to open a simple editor such as Notepad or WordPad.   However, certain editors may actually do more harm than good.   While Notepad is perfectly fine to use when editing your web.config files, it has been our experience that WordPad may actually cause unexpected errors.  

While I am not entirely sure what goes on behind the scenes that introduces these errors; I suspect that WordPad may not translate certain characters correctly and instead insert an alternate character with the nearest ASCII value.  

We strongly suggest that you avoid WordPad for those times you need to quickly edit an XML file; you may find yourself swifting through your file for a mysterious error.