I just installed all the mods needed for play on the primary server using the Arma3Sync "Getting Started Tutorial" on the UOWiki, here: http://www.unitedoperations.net/wiki/Getting_Started_Guide_(Arma_3)
I followed each step, until step towards the bottom when it says, "You can now launch the game by selecting the newly added server and click "Start Game"." I tried it, and it would open Arma 3, but it would stay on the splash-screen where it just says "Arma 3", and this would not change, as if it was frozen, except the fps counter in the top right stayed at 10 for a few moments, then would flicker to 2 or 3, and then back to 10.
So, as the tutorial suggests, if I had trouble connecting that way, I could "navigate to the Multiplayer server browser, click the button labeled "Remote" in the bottom right-hand corner and enter the following information into the corresponding boxes:
Port: 2402 ".
There must have been an update to the interface since this tutorial was written, and there is no longer a "Remote" button like from before and previous Arma's. So, I assumed "Direct Connect" is the same thing, and tried that. I remember from Arma 2 that it would take a few moments for the server to pop up when trying to find it in this manner, so I waited, and waited, and waited, and nothing happened. The only option that would come up would be "Host a server".
The final thing I tried was the "Server Browser in Launcher" button in the bottom right of the multiplayer screen, and funny enough, I found the server. However, the launcher would not let me connect to the server because I did not have any of the mods to do so — wait, what? I had installed them with Arma3Sync...
Is this a problem that had already been dealt with somewhere deep in the forums? I noticed that no one has been on the primary server for at least two days, is there some kind of maintenance going on? Any help would be appreciated.