I downloaded 'AjaxUploader 3.0 2014-03-13' to solve our compatibility issues with IE 11.
I am testing wIth a net_cs/samples/simple-upload.aspx
When I upload a file in IE11 standards mode, the uploaders stalls about 19%.
I can still cancel the upload.
When I add my domain to the IE11 Compatibility View Settings, the upload works without a problem.
I have tested this on two different machines.