Why do you have such an unusual IP address? Is that something you manually set on the Humax configuration screen, or perhaps a default from the factory reset? I don't think your network would be very happy with it as it is on the wrong subnet.
In a situation like this it is best to start from scratch and take an absolutely methodical approach, make no presumptions, and eliminate as many factors as possible. I always advise using the simplest possible network arrangements until you have something working, and that means a direct wired connection. David_Brown_UK usefully tells us you need a cold start to switch between a wired network and a WiFi dongle, I didn't know that.
Forget the custom software for the moment, you need to concentrate on why your Humax cannot access the standard TV portal using the standard firmware. I see no need to reset to factory, but it can do no harm. Revert to standard firmware if you currently have the custom firmware installed. Connect to the router by wire if at all possible, and set the Humax to DHCP.
Once you have re-established connection to the standard TV portal (thus proving the network), you then might consider re-introducing WiFi (though I would prefer to leave that until later). Check you can get FTP access from your PC (needs to be enabled at the Humax).
When you get that far, install the custom firmware and confirm you can see the initial browser control panel (if the /mod folder is already present from previous attempts, you might go straight to the full WebIF), then initiate the custom software download (if necessary).