A NL-Network-03 means that the destination port was not reachable. What did you get for those requests as responses during the recording?
Could it be a proxy issue?
What do you mean by "add localhost in runtime setting"?
Answering second half - how to add localhost in runtime setting:
It should be there by default in runtime. You need to just check the box to select it. Incase it is not there use the + button highlighted in the image and add localhost:7100 [if local host doesn't work please try 127.0.0.1:7100]