Just re-tested against https://en.wikipedia.org/w/index.php?oldid=678508180 ([[Ray County, Missouri]]) and drag-n-drop of images didn't work on IE still.  It did work on FF and Chrome, though.

In IE, clicking on the Route 13 sign ([[File:MO-13.svg]]) shows the Media highlight.  Click off of that and you get the following exception:
   SCRIPT5022: Nested change of newModelSelection File: load.php, Line: 832, Column: 517

IE's debugger has this call stack:

    ve.ce.Surface.prototype.changeModel [Line: 832, Col: 517], load.php
    ve.ce.Surface.prototype.handleObservedChanges [Line: 819, Col: 510], load.php
    ve.ce.SurfaceObserver.prototype.pollOnceInternal [Line: 836, Col: 73], load.php
    ve.ce.SurfaceObserver.prototype.pollOnceSelection [Line: 835, Col: 625], load.php
    ve.ce.Surface.prototype.onDocumentSelectionChange [Line: 791, Col: 569], load.php
    jQuery.event.dispatch [Line: 65, Col: 907], load.php
    elemData.handle [Line: 60, Col: 384], load.php
    ve.selectElement [Line: 62, Col: 281], eval code (48)
    ve.ce.Surface.prototype.preparePasteTargetForCopy [Line: 816, Col: 530], load.php
    ve.ce.Surface.prototype.onModelSelect [Line: 815, Col: 591], load.php
    oo.EventEmitter.prototype.emit [Line: 65, Col: 545], eval code (46)
    ve.dm.Surface.prototype.setSelection [Line: 578, Col: 532], load.php
    ve.dm.Surface.prototype.changeInternal [Line: 580, Col: 371], load.php
    ve.dm.Surface.prototype.change [Line: 579, Col: 351], load.php
    ve.ce.Surface.prototype.changeModel [Line: 832, Col: 609], load.php
    ve.ce.Surface.prototype.handleObservedChanges [Line: 819, Col: 510], load.php
    ve.ce.SurfaceObserver.prototype.pollOnceInternal [Line: 836, Col: 73], load.php
    ve.ce.SurfaceObserver.prototype.pollOnceSelection [Line: 835, Col: 625], load.php
    ve.ce.Surface.prototype.onDocumentSelectionChange [Line: 791, Col: 569], load.php
    jQuery.event.dispatch [Line: 65, Col: 907], load.php
    elemData.handle [Line: 60, Col: 384], load.php
    ve.ui.LinearContext.prototype.onContextChange [Line: 904, Col: 976], load.php
    oo.EventEmitter.prototype.emit [Line: 65, Col: 545], eval code (46)
    ve.dm.Surface.prototype.emitContextChange [Line: 575, Col: 206], load.php
    ve.dm.Surface.prototype.setSelection [Line: 578, Col: 682], load.php
    ve.dm.SurfaceFragment.prototype.select [Line: 590, Col: 861], load.php
    Anonymous function [Line: 760, Col: 529], load.php
    ve.ce.FocusableNode.prototype.onFocusableMouseDown [Line: 760, Col: 436], load.php
    jQuery.event.dispatch [Line: 65, Col: 907], load.php
    elemData.handle [Line: 60, Col: 384], load.php