Here's a new rpt with no mods enabled: http://pastebin.com/Gv172mEk

19:53:40 Campaigns\dfa.pbo - unknown

????

@Xeno

Yeah, I noticed that too. Apparently it's a campaign / set of missions.

https://forums.bistudio.com/topic/186001-sp-campaign-delta-force-altis/

Installation:
Extract "DFA.pbo" to your "Steam\SteamApps\common\Arma 3\Campaigns" folder.

The developer wrote that this is the way to install it, but I don't think you are supposed to throw any files inside the Campaigns folder (which doesn't even exist, you have to make one), similar to how you are not supposed to put files inside the Addons-folder.

ref: https://forums.bistudio.com/topic/168277-cba-community-base-addons-arma-3/page-31

Hello,

please try to remove the dfa.pbo file and try to run the game again. Should the crashing persist please, let us know.

Thank you

I already did that. Sorry guys. The issue still persists.

Have no idea how that got there. Someone over in the CBA thread told me to remove that too. I did and the exact same error happens in the exact same manner.

Would you like a new report?

EDIT: I see now that I did put the PBO there per the author's instructions. Regardless, the issue persists. Thanks for the suggestion.

Someone over in the CBA thread

Hi.

Yes please. Also don't only start the game, but let it crash and post the RPT then.

I'm a little unclear by these instructions. The game is crashing. That's why I started this ticket.

Could you be a little more clear. The second I click on OK after selecting LAN/Internet I immediately CTD with the error messages provided in this thread.

1. Start game
2. Make it crash
3. Go to %LOCALAPPDATA%/Arma 3
4. Pick newest rpt file and upload it

I'll post another report later tonight. In the meantime, should I delete the (now empty) Campaigns folder? I take it it's not used for anything?

Here's another report: http://pastebin.com/99qQkgYU

Strange. There is still no crash recorded in that RPT file. It looks exactly like the game was aborted with Alt+F4. I'm running out of ideas.

You could try this:

1. go to your games main directory:

C:\Games\Steam\steamapps\common\Arma 3

and delete these two folders (or make a backup):

Missions
MPMissions

2. go to your profiles folder:

%USERPROFILE%\documents\Arma 3 - Other Profiles

then enter your main profile (you might want to do this for every profile, if you have more than one)
and delete the following folders:

missions
MPMissions
Saved
UserSaved

3. finally go to:

%LOCALAPPDATA%/Arma 3

and delete the folder:

MPMissionsCache

Will I lose anything by doing this?

I guess one part of this that is really confusing for me is that I have two very specific error messages that I've shared here. Do they not point us in any direction at all? I just am really confused why "Include file x\cba\addons\main\script_macros.hpp not found" and "Unable to INIT DXGI" aren't helping point us in a direction.

Obviously the game is looking for and not finding this CBA macros script. Does anyone know what that is?

And DXGI relates to my graphics card, correct? Could that be the problem?

Also, Killswitch posed a possible solution which I'll try too:

Try this:

1. Make copy of the Arma 3 MPMissions folder (C:\Program Files\Steam\steamapps\common\Arma 3\MPMissions) somewhere safe.
2. Delete all files from the Arma 3 MPMissions folder (C:\Program Files\Steam\steamapps\common\Arma 3\MPMissions)
3. Start Arma again
4. Try to launch a hosted LAN MP server and see if it works without crashing

If that works, you have a MP mission file that does this in the description.ext (or a file included in description.ext):
#include "\x\cba\addons\main\script_macros.hpp"
...for some unknown reason. The fix is to find and remove that mission.

And I want to thank you Commy from the bottom of my heart, man. You've invested more time in this than even Bohemia at this point and it will not be forgotten. Thanks so much.

Just an update:

After deleting everything in my MP missions folders in My Documents, the ARMA 3 root and the local appdata folders, the CTD has finally stopped. Thanks guys.

I'm now adding missions back on a "what I'm currently using" basis. Still haven't found which mission was causing the issue, but it is indeed fixed.

I have to still say that launching a vanilla game with no mods should not force the client to have to have every mod enabled for every mission in their mission folder just to host LAN. This has got to be a bug.

Anyway, problem solved.

Solved on user's side