Does anyone know why using 'fileEntry.file' keeps failing in my Windows 8 app when trying to read a file?

Does anyone know why using 'fileEntry.file' keeps failing in my Windows 8 app?

If I use the following code it fails:

Windows.Storage.StorageFile.getFileFromApplicationUriAsync(new Windows.Foundation.Uri(cordova.file.applicationDirectory + 'www/assets/pages/en/navigation.html')).done(usethisfile, fail);

function usethisfile(fileEntry) {
    console.log("Im going to use the file... " + fileEntry.path);
    fileEntry.file(function (file) {
        var reader = new FileReader();  
        reader.onloadend = function() {
            console.log("Successful file read: " + this.result);
        };  
        reader.readAsText(fileEntry);   
    }, onErrorReadFile);
}

but if I remove the 'fileEntry.file' part it works fine:

Windows.Storage.StorageFile.getFileFromApplicationUriAsync(new Windows.Foundation.Uri(cordova.file.applicationDirectory + 'www/assets/pages/en/navigation.html')).done(usethisfile, fail);

function usethisfile(fileEntry) {
    console.log("Im going to use the file... " + fileEntry.path);
    //fileEntry.file(function (file) {
        var reader = new FileReader();  
        reader.onloadend = function() {
            console.log("Successful file read: " + this.result);
        };  
        reader.readAsText(fileEntry);   
    //}, onErrorReadFile);
}

The official docs say to use 'fileEntry.file': https://cordova.apache.org/docs/en/latest/reference/cordova-plugin-file/index.html and I already have the app running on both the Android and the Apple stores so I'm hoping I can continue to use all the current functions that already use 'fileEntry.file' for the Windows version.

The error I get is: 0x800a01b6 - JavaScript runtime error: Object doesn't support property or method 'file'.

I'm using Cordova via the command-line and Visual Studio to run it if that helps at all.

Not 100% sure but try adding e argument when you define the onloadend method