I have a Lenovo ThinkPad W540 with Intel® Dual Band Wireless-AC 7260 Plus Bluetooth
and the problem is I can't connect to a third party device which broadcasts ad hoc wifi network.
This ad hoc network does not share Internet connection, it is purely to connect with this device via the dedicated application.
I tested connection with other ad hoc networks and looks like Wireless-AC 7260 can only connect to ad hoc wifi networks which share Internet connection. If they do not share Internet connection then Wireless-AC 7260 does not set up IP properly via DHCP.
I tried different drivers and different operating systems (Windows 7, Windows 8). Nothing helps...
We were able to connect but we would like to do more testing. Would you share the models of those broadcasting devices?
You may want to try the option "Add a device" given in Windows* 8/8.1 for WiFi Direct devices. I guess you already tried with Wireless Hosted Network.