IE11 Grey screen with Build 2017.1.1821 Follow

HI

I just updated to Build 2017.1.1821 and now using IE11.0.9600.18524 I get a grey screen, the bg color of Upsource (Chrome works fine). Looking at the Console I see the following error:

SCRIPT5009: 'Promise' is undefined
File: application.e016be01f5e91fdce206.js, Line: 1, Column: 7418

[...]var n=setTimeout(a,12e4);b.onerror=b.onload=a;var t=new Promise(function(c,a){d[e]=[c,a]});return d[e][2]=t,f.appendChild(b),t},c.m=e,c.c=f, [...]

Using compatibility view does not resolve the problem.

Any ideas what could be the cause of this?

Best regards

Devon