Only few devices were connected but not all

I have over 40 devices but only 2-3 were connected suddenly.  I tried to reboot and even reset .. nothing worked.  I then login (http://www.routerlogin.net/start.htm) to check how many devices are connected under Security\access Control and found that yes only 3 are connected and the reason was for some reason the "Turn on Access Control" and "Allow all new devides to connect" are unchecked so and checked them and everything works again!