HTTP Error 405.0 - Method Not Allowed with Put when attempting to upload a file

Question

My previously working update function now returns a 405 error when it is run. This is after I added the fileReader functionality to facilitate file uploading for a pictures. How could I now have a HTTP verb error (which is what 405 is to my understanding) if my ajaxCall is untouched from it's working form?

function update()
{

//picture specific upload stuff
var reader = new FileReader();
var file = $('#fileUpload')[0].files[0];
reader.readAsBinaryString(file);
//What is readerEvt?
reader.onload = function (readerEvt)
{
    //get binary data then convert to encoded string
    var binaryString = reader.result;
    var encodedString = btoa(binaryString);

    //normal update fields
    emp = new Object();
    emp.Title = $("#TextBoxTitle").val();
    emp.Firstname = $("#TextBoxFirstname").val();
    emp.Lastname = $("#TextBoxLastname").val();
    emp.Phoneno = $("#TextBoxPhone").val();
    emp.Email = $("#TextBoxEmail").val();
    emp.StaffPicture64 = encodedString;
    emp.Id = localStorage.getItem("Id");
    emp.DepartmentId = localStorage.getItem("DepartmentId");
    emp.Version = localStorage.getItem("Version");
}
ajaxCall("Put", "api/employees", emp)
    .done(function (data) {
        $("#myModal").modal("hide");
        getAll(data);
    })
    .fail(function (jqXHR, textStatus, errorThrown) {
        errorRoutine(jqXHR);
    });
return false;
}