Most times when I am trying to use Airserver against my Ipad I get this sad looking message:
When Googling it you might find "solutions" like this one. Easy solution, just make them reconfigure the network, I don't see any challenges with that at all. So most of the time I just create a shared network on my own device and connect the PC and devices to that one.
But travelling abroad it might become an expensive solution, and maybe you need/want to be connected to the network where you are to be able to reach other kind of resources.
The solution are much easier then you think, just drop the app. You don't need it
With AirServer installed on you PC you can detect the PC as a "Screen Mirroring" endpoint.
No app necessary and and you don't have to modify the network or use your own shared network on you device. It's just like you have connected a Apple TV to the screen :-)
You can do just about the same on Android also, but the screen will not be fitted to the device in the same way and I have noticed that it some times fails when doing this on Android.