Something wrong with my expo xde(no qrcode)

i start my project with Expo XDE, it seems no error happend, but i can not get the qrcode or the url !
so i can not open it in expo mobile!

hey, common debugging for this is usually:

closing expo
checking to make sure you have stable internet
deleting all node_modules
installing npm 4.6.1
run npm install or yarn install
restart expo and try again.

usually fixes this problem, but it may be more complicated