Hi,
I have tried to set up online multiplayer in PIE. From research I know that it’s possible but a bit unstable since the project files won’t match 100% even if you copied the same project. I have changed .ini port to 5001, opened the port on my firewall and router, checked that it’s open with software. I made two shortcuts to the UE4Editor.exe like this (client and server):
“D:\Epic Games\4.10\Engine\Binaries\Win64\UE4Editor.exe” D:\unreal_projects_d_drive\HatCatGame\HatCatGame.uproject 12.345.123.456 -game
“D:\Epic Games\4.10\Engine\Binaries\Win64\UE4Editor.exe” D:\unreal_projects_d_drive\HatCatGame\HatCatGame.uproject Dev_Level?listen -game
(game name: HatCatGame level name: Dev_Level) Both shortcuts open the game, and if I use them on my computer I get two windows - one with client and one with server. I sync the project by github with a friend, use the shortcuts and we just get one server window each.
What I think could be the problem (with my limited knowledge): - My friend changes his shortcut to fit the new file locations so they differ. For example his Epic Games folder is on E: and the HatCatGame on F:. - The port is not in the shortcut. Maybe it should be like this: 12.345.123.456:5001? - I found the command “Open :” in a thread, but I can’t open the console after using the shortcut so I didn’t try it out. - I tried changing the IP to my local IP and to my public IP, nothing happens.
Thanks for you help! 
Some threads I have read for reference: Internet Multiplayer - Blueprint - Unreal Engine Forums Network testing across multiple computers - Blueprint - Unreal Engine Forums [UE4.7.2] Getting userId: Invalid Error for Multiplayer - Multiplayer & Networking - Unreal Engine Forums