If you are having trouble sending via wifi, then it might be a problem with your wifi configuration. 
Fortunately there is an alternative way of importing a session.
Use “import from iDevice”
First thing to do is to back up your iPhone. Do this in iTunes.
Find the iDevice to the left in the iTunes menu. Right-click and choose “Backup”

Now open Hindenburg.
File / import from iDevice
Choose the Device
Now you can browse all your sessions