Why is Boxer opening one particular file of mine in hex editing mode?
Boxer must be detecting that there’s a null character in the file. The presence of even just a single null character (ie, the zero byte) in a file means the file must be classified as a hex/binary file, and cannot be edited in text mode. There’s an option that you might find more flexible/powerful in this regard. On the Configure|Preferences|Editing 2 dialog page, under Editing Options, select: “Display a dialog with options for handling null characters” This will allow you to choose how Boxer handles files with null characters. Options include deleting them, converting them to spaces or other characters, or opening them in hex mode.