Your website is publishing multiple conflicting Internet Explorer emulation directives including a request to render the page in an emulator of Internet Explorer 7.
https://msdn.microsoft.com/en-us/library/jj676915.aspx
<meta http-equiv="X-UA-Compatible" content="IE=EmulateIE7" />
<meta http-equiv="X-UA-Compatible" content="IE=9" />
<meta http-equiv="X-UA-Compatible" content="IE=edge" />
Twitter’s widgets JavaScript supports Internet Explorer 9 and above.