Fix The Blue Screen Of Death On Your Pc

Windows Phone 8 Lumia 920 does not connect to company university WLAN any more Certificate issue

I had my Lumia 920 WP8 phone connected to my company / university WLAN at KIT  (wkit-802.1x) for months without issues. A few days ago, it started to refuse to connect to the WLAN. It kept asking my for username and passwort and then just told me "Anmeldung nicht möglich" (german). I think the error message in english could be something like "Cannot connect" or "Could not connect to WLAN".

How-i-fixed-it:
The Problem seems to be caused by an issue with the root certificate the Network uses (Deutsche Telekom Root CA 2). I downloaded the certificate again as described on my university WLAN help page, sent it to myself by email and opened it on my phone. WP8 asked me to install the certificate and i confirmed.
After that, i tried to connect to WLAN again and it works!

for details click below