It’s been a while since I was troubleshooting prompt for credentials. The last time I was happy to find the root cause and how to fix this (you can read about it here).
Now the same issue seems to come back. But this time it has nothing to do with proxy settings. This time it has to do with KB3114351 and KB3114372 from December 8, 2015.
There were besides security related updates also some major design changes implemented as described more in depth in KB3135145:
- Cloud Based Discovery
- UPN Enforcement for OrgID
- SIP Autodetection from Azure