If you are experiencing game crashes when you try multiplayer, read this.

No clue about the EA desktop app. From what I can tell, the app's still in beta and lacks any launch option or command-line features. If by any chance, you have Origin as a companion app for Titanfall [like you need Origin to play even if you bought the game on steam] you can try the launch option.

alternatively, get the Northstar Client. It's a community made Multiplayer client that lets players make and join custom servers that are DDOS free. not only that, but you can also play brand new game modes, get mods and custom skins

1. This explains it well 

Thank you so much. This was the fix for my issue. I had spent 2 hours with EA Support with them trying to give me connection issue articles. I then went and searched on my own and found this and sent it to them saying this is the problem I had and this is what fixed it.

So I typed that stuff in the command in origin.  The game loaded and I was excited to see that it didn't crash after two seconds as it had been doing.  Yeah, I got to hear the TF music in the lobby!  Progress!  Unfortunately, it didn't allow me to set a different network as active.  It also initially didn't have me as active in any network...which maybe is what that command line does, however doesn't allow you to actually play without being in a network.

Eventually I was able to be active in the ADV network again, but alas, it wouldn't connect to any matches.  Also odd, when I highlighted the few player names who were in the lobby, they all showed level zero and zero stats, etc.

Let me know if you come across a solution that works.  I’ve since downloaded Northstar Client.  I was able to play three days, but half way through day three I kept getting an “authentication failed” message and couldn’t get it to work the rest of that day.  I’m hoping it was just an issue with the master server.  Haven’t tried it since then, I’ll find out on Wednesday if it’s working again or if I have to go through a bunch of other crap to try to get NS CLient to work again.

An exploit was apparently found in the (base) game and the Northstar developers have taken Northstar's servers down until a fix is out, you can find more info in their Discord.

Greeting. 

First of all, thank you for the support your provided.

But my problem is not solved, is there any other ways to solve this problem?

Thank you.

If this didn't solve it for you, it could be due to bunch of other factors. Kindly detail what exactly is happening and what troubleshooting you have tried. If you find it easier, shoot me a DM on discord. I'll be happy to help in any way I can; 

Discord tag: Dhruv Gandhi#6590