show PDF from byte array in javascript

First of all, two things:

• I know, there a lot of similar questions, but none of them helped me finding a solution for my problem
• I'm a beginner - in every single aspect of programming...

Problem: Receiving a byte array from a webservice, I need to show a PDF in Internet Explorer 9. Following code is working in Chrome, but in IE9, all I receive is a dark gray panel, where the PDF is ment to be.

Ext.define('Ext.ux.form.DocumentFrame', {
extend: 'Ext.container.Container',
alias: 'widget.documentframe',
layout: 'hbox',
initComponent: function () {
    var me = this;
    var binaryData = me.value.DocumentData;
    var source = 'data:application/pdf;base64,' + (binaryData);

    Ext.applyIf(me, {
        items: [
                {
                xtype: 'box',
                itemId: 'panel-document-frame',
                width: 600,
                height: 600,
                autoEl: {
                    tag: 'object',
                    width: '100%',
                    height: '100%',
                    type: 'application/pdf',
                    data: source
                }
            }
        ]
    });
    me.callParent(arguments);
}
});

• Is there a problem with the MIME-Type?
• Do I have to encode or decode the byte array?

I just don't understand why this works in other browsers, but not in IE9, especially while giving a path to a stored PDF-File is working without any problems (even in IE9). I do this by setting the data-parameter for autoEl like this:

data: 'content/files/Designer.pdf'

Note: by doing this in IE9, a MessageBox appears: "An Active X Control on this Page Might be Unsafe to Interact with Other Parts of this Page". At the very moment, i do not care about this.

Am I so wrong on trying to show a PDF from a byte array? I'm really stuck on this and any help would be highly appreciated!

Thank you in advance!