Commonwealth-Online-Public/docs/PATCH_MainMenu_Multiplayer.md

MainMenu.swf — Multiplayer button patch guide

Full FFDec walkthrough: see FFDEC_MainMenu_Multiplayer_Guide.md for exact search anchors, before/after snippets, and a test checklist.

Add a Multiplayer item to the title-screen main menu. Selecting it calls root.f4se.plugins.commonwealthOnline.openManager(), which opens the PrismaUI server browser (same as F9).

CRITICAL — edit methods, not the whole script

Never paste the full exported MainMenu.as into FFDec or use Import script on the whole class. That recompiles RequestOptions from decompiled source and breaks Settings → Gameplay / Display / Audio.

In FFDec, edit individual methods (double-click the method under MainMenu traits). FFDec then recompiles only that method and leaves vanilla bytecode (including RequestOptions) intact.

Restore vanilla any time:

.\tools\restore-vanilla-mainmenu.ps1

Prerequisites

• JPEXS FFDec
• Game launched via F4SE with CommonwealthOnline.dll installed
• Loose Interface overrides enabled in Fallout4Custom.ini:

[Archive]
bInvalidateOlderFiles=1

FFDec workflow

1. Copy Interface/MainMenu.swf.vanilla.bak → Interface/MainMenu.swf (start from vanilla every time).
2. Open Interface/MainMenu.swf in FFDec.
3. In the left tree: scripts → MainMenu (class traits list, not “Edit ActionScript” on the whole class).
4. Apply the four method-level edits below (double-click each method to open its editor, save after each).
5. File → Save.
6. Sanity check: patched SWF should stay ~62–63 KB. If it jumps to 64 KB+, settings are likely broken — restore vanilla and retry using method editors only.
7. Copy to Fallout 4/Data/Interface/MainMenu.swf.
8. Test Settings → Gameplay / Display / Audio first, then Multiplayer.

---

Edit 1 — Add constant (class body)

Open the MainMenu class initializer / constants section (or edit at top of class in trait view). After INSTALLED_CONTENT_INDEX:

private const MULTIPLAYER_INDEX:Number = 15;

Index 15 is unused in vanilla (highest is INSTALLED_CONTENT_INDEX = 14).

---

Edit 2 — InitList() — add menu row

In InitList, find the $LOAD push (after $NEW on title screen). Insert before the PS5 transfer block:

         this.MainPanel_mc.List_mc.entryList.push({
            "text":"$LOAD",
            "disabled":!this.HasRecentSave || !param6,
            "index":this.LOAD_INDEX
         });
         if(!this.PauseMode)
         {
            this.MainPanel_mc.List_mc.entryList.push({
               "text":"Multiplayer",
               "index":this.MULTIPLAYER_INDEX
            });
         }
         if(param8 == true)

Use literal "Multiplayer" (no $ prefix) unless you add a row to Interface/Translate_en.txt.

---

Edit 3 — onMainListItemPress() — handle click

In the main switch(this.MainPanel_mc.List_mc.selectedEntry.index), add before case this.HELP_INDEX::

               case this.MULTIPLAYER_INDEX:
                  this.BGSCodeObj.PlayOKSound();
                  if(root.f4se != null && root.f4se.plugins != null && root.f4se.plugins.commonwealthOnline != null)
                  {
                     root.f4se.plugins.commonwealthOnline.openManager();
                  }
                  break;

---

Edit 4 (recommended) — auto-close browser

The plugin also hides the browser when the menu leaves MAIN_STATE, but these SWF hooks close it immediately when navigating away.

4a — Add new method CloseMultiplayerBrowser

In FFDec: MainMenu → right-click → Add script / add method:

      private function CloseMultiplayerBrowser() : *
      {
         if(root.f4se != null && root.f4se.plugins != null && root.f4se.plugins.commonwealthOnline != null)
         {
            root.f4se.plugins.commonwealthOnline.closeManager();
         }
      }

4b — Edit set currentState

After this.strCurrentState = param1;:

         this.strCurrentState = param1;
         if(param1 != this.MAIN_STATE)
         {
            this.CloseMultiplayerBrowser();
         }
         this.UpdateButtons(param1);

4c — Edit onMainListItemPress

After the while(this.strCurrentState != this.MAIN_STATE) loop, before the switch:

            if(this.MainPanel_mc.List_mc.selectedEntry.index != this.MULTIPLAYER_INDEX)
            {
               this.CloseMultiplayerBrowser();
            }

---

Test plan

Step	Expected
Main menu shows Multiplayer between Load and Add-ons	Yes
Click Multiplayer	Server browser opens
Open Settings → Display	No crash
Open Settings → Gameplay / Audio	No crash
Select Continue while browser open	Browser closes
F9	Still toggles browser

---

Reference

Full decompiled class (do not import wholesale): scripts/MainMenu.as

Plugin API registered in CommonwealthOnline.dll:

• root.f4se.plugins.commonwealthOnline.openManager()
• root.f4se.plugins.commonwealthOnline.closeManager()