Custom Multiplayer Maps

[LBBNigma]

Hello,

I am still new here but i have been searching for an answer to this for 2 days now. And i am confident enough there is no post about this yet.
I have a handful of friends that decided to get together and all of us got the game with the latest sale. Strange thing is that I can only be the host, as for some unknown reason if any of the other host they do not show up on the server list. But that is not the issue i need help with.
We have been playing for a couple of days now and really would like something different from the default multiplayer missions.
I have dived into making our own, and followed all the guides i could find on it. Exported a custom map. Yet it does not show up on the list. I then proceeded to download other custom maps. Which presumably work since they have downloads in the three digit numbers. Yet those don't show up either.

What do i need to do to get custom multiplayer maps to show up?
Is there a mod required?

[LBBNigma]

Running over all of the steps again I have found what seems to be the problem.
I noticed one of the custom mission i didn't remove now seemed to work.
Comparing the files i realized my own custom mission wont save as a .misge file. Instead always going as a .mis file.
No matter what side i pick as part of the campaign settings in the editor.
Is there a way to change the mission to a .misge?

Edit:
Digging through all the steps again carefully I noticed i was saving the mission and campaign by default ways.
I forgot to actually export the game as a .misge file and simply only used the .mis file.
It seems to be working now.

Apologies for the useless thread.