When attempting to compare two files using vsdiff from a command line, if the second file specification is exactly 16 characters long, the 16th character is being dropped and vsdiff displays a popup reporting the file (minus the 16th character) can't be found. I recently noticed this bug in Beta 4 and just confirmed it's also in Beta 6. For example: vsdiff ..\..\app.config Host01.exe.config In this case, the "g" is lost in vsdiff processing of the command line args. This problem does not occur for the first filename.