I implemented an ajax file upload Everything works fine in all browsers, but Safari on iOS. As response I get an Internal Server Error.

I checked my serverside code, but there's nothing wrong. I even get the error, if I write a die(); at the first line of code in the serverside PHP script. It seems as if Safari uploads the picture wrongly. Maybe somebody can help me fix this bug. Thanks in advance!

This is the HTML-Code:

<inputtype="file"id="pict"accept="image/*">
<inputtype="text"id="field1">
<inputtype="text"id="field2">
<buttonid="send">Send</button>

And this the Javascript:

    var files = false;
 
    $('#pic').on('change', prepareUpload);
 
    function prepareUpload(event) {
        files = event.target.files;
    }
 
    $("body").on("click", "#send", function () {
        uploadTB();
    });
 
    function uploadTB() {
        var postdata = new FormData();
        if (files !== false) {
            $.each(files, function (key, value) {
                postdata.append(key, value);
            });
        }
        postdata.append("field1", $("#field1").val());
        postdata.append("field2", $("#field2").val());
        $.ajax({
            url: 'http://example.org/index.php',
            type: 'POST',
            data: postdata,
            cache: false,
            processData: false,
            contentType: false,
            success: function (data) {
                console.log("sucess");
            },
            error: function (jqXHR, textStatus, errorThrown) {
                console.log(jqXHR, textStatus, errorThrown);
            }
        });
    }