If you're using a PC, you may have to download Microsoft MIDIBerry. According to this helpful article, you may also need loop midi to set up a virtual MIDI port.
If using a Mac, you'd use MIDI Monitor for the same function.
If you've already taken these steps, we'd recommend closing all other MIDI programs (like Bitwig and Ableton Live) and then reopening the SenselApp. Then, follow these steps to resend your map again.