Windows 10 Enterprise 2016 LTSB x64
GeForce GTX 750 ti
Short description of error
The edges marked as Freestyle Edge in Edit Mode are not highlighted, but the edge appears in freestyle render as expected.
Exact steps for others to reproduce the error
1 - Goto Edit Mode.
2 - Select any edge.
3 - Ctrl+E and pick: Edge Data->Mark Freestyle Edge.
4 - Note that the edges are not highlighted.