Rain(/All),
Ensure you have Epoch 1.0.5.1 & Overwatch (0.2.5). These should be placed in your Operation Arrowhead folder;
C:\Program Files (x86)\Steam\steamapps\common\Arma 2 Operation Arrowhead\@DayZ_Epoch1051
C:\Program Files (x86)\Steam\steamapps\common\Arma 2 Operation Arrowhead\@DayzOverwatch
Open the Arma 2 launcher and it should ask you to locate these paths the first time you run it. if not, you can add them later in steps 11 & 12.
I missed this step, so the following instructions and attached screenshots show the full how-to. if you already have the paths located, then skip steps 11 & 12.
As always, ensure you run A2 and then A2OA once after re-install from steam. If you're simply swapping launchers, you can skip this.
Within A II Launcher;
1. 'Addon Options' Tab
2. Add search directory
3. Located directory which contains addons (not each addon folder) [C:\Program Files (x86)\Steam\steamapps\common\Arma 2 Operation Arrowhead]
4. Ensure Overwatch is at top of list or you will encounter an error on joining server
5. 'Addons' Tab
6. Select Overwatch and Epoch addons - drag to Group 1
7. Ensure 'play online' is ticked
8. Ensure Arma II - CO is selected or you will encounter an error on joining server
9. Tick addons to run (including the group)
10. 'Launch Options' tab
11. Select the Arma 2 .exe
12. Select the A2OA .exe
13. (OPTIONAL) select any launch options - User profile/no splash etc.
14. 'Online' tab
15. (OPTIONAL) add step 16. to favourites - then double click to select
16. Add the server IP(37.152.48.105) and Port (2302)
17. Start Game
Good Luck,
AC