Beginner compile trouble: warning C4244: 'return': conversion from 'lv_style_int_t' to 'lv_blend_mode_t', possible loss of data

I’m new to LVGL and this environment. I’m running the latest VS 16.10.0 on Win 10, and have cloned (I think) the latest LVGL.Simulator.

I’m able to compile and run the X64 Release but I get numerous warnings about:
“warning C4244: ‘return’: conversion from ‘lv_style_int_t’ to …”

Running the EXE displays the GUI, but any attempt to interact causes the app to not respond.

Any ideas guys?