Installed DLP 15 with ICT.
The agent shows the ICT plugin loading but the classifcation buttons are missing in office applications [ERROR]   Mon Jan 29 10:34:07 2018 Thr   872 | CcsSecConfWebServWrapper.cpp>csw::mls::CcsSecConfWebServWrapper::GetConfiguration(422): {0xC00CE556}> Error occurred while contacting http://ict.domain.local/ICT/webservice/Service.asmx. WS Status Code: 401
 

the domian is not added to local intranet sites for windows integrated authentication to work properly

In order to fix this they will need to add the ict.domain.local (*.domain.local or http://ict.domain.local will also work), to the local intranet sites.