"multiplayer.packErrors" Triggers on Clean Vanilla Worlds / Handshake Memory Leak

Short description of the issue

The global red chat error message "At least one of your resource or behavior packs failed to load." (multiplayer.packErrors) consistently prints into the chat buffer upon loading any world session, including completely fresh, brand-new Vanilla worlds with zero active add-ons, zero marketplace content, and Education Features turned completely off.

This is a main menu UI cache memory leak on PC. When the client initializes at the main menu, the engine processes profile handshakes and local developer paths (Shared vs User ID folders). If a minor validation discrepancy or catalog timeout occurs during this main menu startup sequence, the engine flags multiplayer.packErrors to true. When a player enters any clean simulation world, the HUD rendering engine fails to clear the main menu's active flag, forcefully printing a false-positive visual alert to the screen the exact second the terrain finishes building.

Steps to reproduce the issue

1. Ensure the Windows PC client is updated to v1.26.51. (or v26.51)
   

2. Initialize the game to the main menu (allowing global marketplace catalog packages and active account profile streams to index in the background).
   

3. Select "Create New World".
   
   Ensure no resource or behavior packs are active (pure vanilla setup) and ensure Education Edition is toggled OFF.
   

4. Load into the brand-new vanilla world session.
   

5. (Optional verification test): Altering the local language .lang file string for multiplayer.packErrors to a blank value successfully hides the text string, but leaves behind an empty blank newline execution break at the top of the chat stack, proving the engine is actively running the stale main menu hook inside the active world space.
   

Expected result

The player spawns into a pure vanilla world with a completely silent, clear, and unblemished chat log window.
(or just a blank chat window)

Actual result

The chat window instantly displays the bright red text error string: "At least one of your resource or behavior packs failed to load." despite no custom files, third-party frameworks, or behavioral dependencies being requested or loaded by the active world layer.

(Note: Custom addons are confirmed to be fully operational and error-free when manually checked via the Content Log GUI; this is a pure HUD rendering buffer leak.

Attached screenshots demonstrate the identical red message rendering in both an addon-heavy environment and an absolute clean-slate vanilla world block configuration).


(images attached from also from MCPE-175149 as a reference & identical issue when found in v1.20.30 then found to be fixed a couple bug fix patches later)