Well i get this sometime with my DLink router. What i do is just a soft reset of the router. Go to your router setupo and reset it. If you can. My Linksys router doesnt have that option so i have to reset the PC a couple of times for it to allow the connection.
I do not accept support questions via EMail, PM, IM or my G+ page!
Phone: LG Optimus G Pro
Running: Stock JB from LG with Nova Launcher