When I open Kdenlive, under my Video Window, there are only two buttons, Clip Monitor and Project Monitor. With every video I see of Kdenlive they have 3rd tab there says record Monitor, which is not on my version, which is Version 17.04.3 using KDE Frameworks 5.18.0, Qt 5.5.1 (built against 5.5.1, The xbc windowing system.
The OS on this Machine, I call My Video Editing Beast, is Linux Mint 18.2 Sonya Cinnamon