"Unrecognized file type" or "Error opening file" or "Error parsing file contents" are all errors we typically encounter, when we provide incorrect input files to applications.

I did that today, when burning a CD image file.  Here's what I got:

I had given it the ISO file; it wanted the MDS.  Instead of spewing the usual error message, I found this to be much more effective, helpful, and pleasant to use.