An issue was reported to me recently where a user was unable to login to Skype for Business / Lync.
The steps attempted to diagnose this issue were as detailed below.
- Attempted to login with my Skype for Business user account (fail)
- Run Skype for Business as my user (success)
- Run Skype for Business as Administrator (success)
- Try another computer as that user (fail)
The user was logged into a computer on a domain where AD FS is configured for Office 365 and attempting to authenticate against a different organisations Skype for Business tennant.
After endless troubleshooting, I discovered a blog post with someone having the same issue and documenting a fix.
In my situation, as the user was using Microsoft Office 2016, the resolution was to open regedit and create the following entry.
Name: DisableNTCredentials Type: REGDWORD Value:1
I hope this helps someone somewhere!