Strange glitch in my script. Please help!

Question

I've been working on a script that would help a friend of mine to prep photos for his web-site. It was working just fine until after some small change it suddenly started telling me this: "Cannot open the file because the open options are incorrect". The ExtendScript Toolkit highlights line 44:  var doc = app.open(file);
I've looked at all variations of the app.open(); function but can't seem to understand what is wrong.
I'm hoping someone will notice the problem. Thanks in advance!
#target photoshop
var outputWidth = 1500; 
alert("You will now need to select a folder with photos to be processed.");
var inputFolder = Folder.selectDialog("Select Input folder");
// Creating a new  subfolder based on user input
var outputFolder = new Folder(inputFolder + "/" + "PROCESSED"); 
outputFolder.create();
var Destination = outputFolder.path + "/" + outputFolder.name;
// Replacing %20 with space for clean alert
var CleanDestination = Destination.replace('%20', ' '); 
var CleanerDestination = CleanDestination.replace('%20', ' '); 
var startRulerUnits = preferences.rulerUnits; 
app.preferences.rulerUnits = Units.PIXELS;
// our web export options
var options = new ExportOptionsSaveForWeb();
options.quality = 70;
options.format = SaveDocumentType.JPEG;
options.optimized = false;
options.includeProfile = true;
if (inputFolder != null && outputFolder != null) { 
    var files = inputFolder.getFiles(); 
    for (var i = 0; i < files.length; i++) { 
        var file = files[i]; 
        var doc = app.open(file); 
        // get a reference to the current (active) document and store it in a variable named "doc"
        doc = app.activeDocument; 
       //get the filename without the extension 
        var Name = app.activeDocument.name.replace(/\.[^\.]+$/, ''); 
       if (doc.height > 1000) {
//build up the output file name and path 
         var goodFolder = new Folder(outputFolder + "/" + "READY FOR WEB"); 
        goodFolder.create();
        var saveFile = File(goodFolder + "/" + Name + "-web" + ".jpg"); 
// do the resizing.  if height > width (portrait-mode) resize based on height.  otherwise, resize based on width
        if (doc.height > doc.width) {
        doc.resizeImage(null,UnitValue(outputWidth,"px"),null,ResampleMethod.BICUBIC);
        else {
        doc.resizeImage(UnitValue(outputWidth,"px"),null,null,ResampleMethod.BICUBIC);
else {
   //build up the output file name and path 
        var smallFolder = new Folder(outputFolder + "/" + "TOO SMALL"); 
        smallFolder.create();
        var saveFile = File(smallFolder + "/" + Name + ".jpg"); 
        doc.convertProfile('sRGB IEC61966-2.1', Intent.RELATIVECOLORIMETRIC, true, true);
        //you need to have a full filepath not a folder 
        doc.exportDocument(/*outputFolder */saveFile, ExportType.SAVEFORWEB, options); 
    doc.close(SaveOptions.DONOTSAVECHANGES); 
        $.writeln('File ' + (i + 1) + ' of ' + files.length + ' processed'); 
//restore ruler units 
app.preferences.rulerUnits = startRulerUnits; 
alert(files.length + " files have been processed into " + CleanerDestination);

Answer 1

JJMack,
Right before var doc = app.open(file);  fails to execute, the value of var file is "~/Desktop/Input/.DS_Store", where Input is my folder with images.