Do you have level in the game named “35.”? From what is seems it is trying to interpret that as part of an IP address, try naming the map you are trying to load by a string instead, see if that helps.
Also why are you Opening second map on the server right at the begin play? Pretty sure that also does not work see https://answers.unrealengine.com/questions/55477/the-difference-of-the-two-functions.html
You can set the default server map in the project in Project Settings → Maps & Modes