Get-CsWebTicket : Failed to connect live id servers.  Make sure proxy is enabled or machine has network connection to live id servers

Run these 3 commands, from an As Administrator CMD prompt, not PowerShell:

ICACLS %windir%\System32\config\systemprofile\AppData\Local /grant *S-1-5-20:(OI)(CI)(RA)

ICACLS %windir%\System32\config\systemprofile\AppData\Local\Microsoft\MSOIdentityCRL /grant *S-1-5-20:(OI)(CI)(IO)(F)

%windir%\system32\inetsrv\appcmd recycle apppool /apppool.name:LyncIntManagement