I can launch Cura with no issues, it runs fine. I can import objects and change settings, but when I click 'slice' it doesn't even show a progress bar on 3.6.0 and on v4 it shows a progress bar but there's never any progress. I've looked in %appdata%\cura\4.0\cura.log and it just stops at an entry like this:
2019-01-11 20:38:46,714 - DEBUG - [MainThread] CuraEngineBackend.CuraEngineBackend._onStartSliceCompleted : Sending slice message took 0.7397589683532715 seconds
I looked in task manager and the system idle process has >95% cpu (cpu is almost completely idle), and like I said I can use Cura just fine (no stuttering when I rotate objects).