NTHP works on one system, not on another

[ronsipherd]

I think this is a new issue - at least to me. New tab home page works fine on my laptop system: 64-bit Windows 7, Firefox 57.0.4 (64-bit). But not on my desktop PC: 64-bit Windows 10, Firefox 57.0.4 (64-bit). When I select New Tab I see a blank white page with Extension (New Tab Homepage) | Search or enter address The only difference I see is the Windows version. Is there an option I'm missing that would correct this?