My point, (if there is one beyond reporting a problem), is that the code needlessly rejects use of a convention which is ubiquitously followed on the Windows platform. I spent enough time reading code to spot the problem (unsuccessfully) that it became obvious that much effort has been made to follow the '\\'as-path-separator convention for Win32-targetted builds. So, clearly, the failure I report is a deviation from the intent apparent in the code. Personally, if I still believed in "should" propositions, I would have the whole world agree that '/' is the one true path separator and that '/' is the root of the whole collection of accessible files locally from an OS. I most certainly do not believe or assert that the rest of the world should accept '\\' as a path separator. However, I can report and predict that an application's failure to do so on the Windows platform can lead to puzzlement and frustration. If I had a recommendation (or "should") for developers, it would be: When a user provides something purported to be a valid path, submit it to the OS and await its complaint before declaring the user's input to be erroneous.