User Configuration > Administrative Templates > Microsoft Office 2016 > Security Settings
User
HKCU\software\policies\microsoft\office\16.0\common\com categories
This policy setting determines whether Office checks that a RealTimeData (RTD) is properly categorized before loading it. If you enable this policy setting Office only loads properly categorized RTD servers. If you disable or do not configure this policy setting, Office does not check that an RTD server is properly categorized before loading it.