Location selection flat out not working!

[let.there.be.light]

Macbook OS 10.9.5 running f.lux version 39.987. In the preferences window, i enter the city i live in (chengdu) and the popup window is empty, so i click on pick a different spot or confirm location... i tried entering other city names, all kinds... country named... zip codes... aleays comes up totally blank... must be a bug? Compatibility issue??? There's no way to manually switch on night mode so the app is useless until i can fix the location fuction...