I know its an old chestnut, but latest posts are a few years ago so be no longer be applicable.
I have just (this morning) installed B4A on my laptop (HP Envy), it appears to work fine. I can open and edit files.
I have also just installed B4A Bridge on my HTC One M8.
When I go Tools>Connect then the phone (with the correct IP address) appears in the connect list, it is the only thing that does.
When I click on it nothing happens except the Bottom of the screen has a banner which alternates between "Trying to connect" and "Connected to HTC One"
On the phone, with B4A Bridge running, it just has "Waiting For connections" which flashes every 5 secs or so. I also get the wifi signal which also flashes up every few seconds.
I have tried clicking "Stop" and "Start" with no effect. The phone does not have a SIM card, does that matter? (My new phone takes a smaller SIM card so I cant try it)
Both devices are showing full strength connections to my wifi (I only have one) and run Google ok.
I also have an HP Elitebook - exactly the same result.