Consider the following scenario:
- You add a new SIP domain in a Microsoft Skype for Business Server 2015 environment.
- You change the default SIP domain to the newly added domain.
- A user signs in Skype for Business mobile application by entering the telephone number.
- The user exits the Skype for Business mobile application and then signs back in.
Cannot sign you in... try later.
This issue occurs because the Dial Plan contains non-numeric or non-alphabetical characters. This causes the telephone number validation failure.
Article ID: 3170199 - Last Review: Jun 30, 2016 - Revision: 1