Cesium not running on Windows Mobile

Hallo, I'm fairly new to Cesium and installed it recently. I created a website where Cesium is running and it works fine on all major browsers for desktop and on my own mobile (Samsung S4, Android browser, Chrome and FF tested). However on another user's mobile (Nokia Lumia 820 , OS Windows, Browser IE) it doesn't run and throws an error message:

An error occurred weile dendering. Rendering hasstopped.
Dann in weisser Schrift:
Truntime Ertor_
Programm failed to link- link Log: internal linking error
Error
At t
(http://webentwicklung.ulrichbangert.de/monice/Celium/build/Celium/Celium.j
At f
(http://webentwicklung.ulrichbangert.de/monice/Celium/build/Celium/Celium.j
At y
(http://webentwicklung.ulrichbangert.de/monice/Celium/build/Celium/Celium.j
At d.prototype_bind
(http://webentwicklung.ulrichbangert.de/monice/Celium/build/Celium/Celium.j
At G
(http://webentwicklung.ulrichbangert.de/monice/Celium/build/Celium/Celium.j
At B.prototype.execute
(http://webentwicklung.ulrichbangert.de/monice/Celium/build/Celium/Celium.j
At n.prototype.execute
(http://webentwicklung.ulrichbangert.de/monice/Celium/build/Celium/Celium.j
At p.prototype.execute
(http://webentwicklung.ulrichbangert.de/monice/Celium/build/Celium/Celium.j
At r.prototypr.execute
(http://webentwicklung.ulrichbangert.de/monice/Celium/build/Celium/Celium.j
At Xe
(http://webentwicklung.ulrichbangert.de/monice/Celium/build/Celium/Celium.j

Note that the user didn't screenshot the message but copied it manually.

I'm suspecting that this mobile is too old and doesn't support WebGL?
Any advice is welcome.
Best regards - Ulrich

BTW: I posted to questions more recently and cannot find them again. Unfortunately I was not able to bookmark the threads?

PS: On the page I posted you need to click one of the drop-shaped markes on the worldmap.

PPS: OS on that phone is Windows 8.1

In the meantime I performed this test:
https://get.webgl.org
This works fine, i. e. WebGL is supported by the browser.
However the Hello-World test produces a similar error message and does not run.

Are the drivers up to date on the device?

See https://cesiumjs.org/troubleshooting/