Dear concern,
The environment has 2008 R2, 2012 R2 and 2016 Domain Controllers & Global Catalog servers, Forest and Domain Functional levels are 2008 R2 also has Lync 2010 server. My concern is that if I demote the 2008 R2 Domain Controller will it makes any impact to run my Lync 2010 server!
Thanks
Babu