📚 The docs are live. The user manual → covers every screen and setting, and the extension docs → show you how to add a store we haven't.
Building an extension is simpler than it sounds, and the easiest route needs no code at all.

How to Install the C++ Runtime in the Decky Plugin

Install the Visual C++ redistributable by hand when a game crashes or reports a missing DLL

Fix game crashes and missing DLL errors when Protontricks doesn't work.

Using Junk Store Pro? The C++ runtime comes down with the game on Epic. See installing game dependencies in Pro instead.

Plenty of Windows games are built against Microsoft's Visual C++ redistributable and won't start without it. The manual route is to put the installer in the game's folder and run it from Junk Store.

Each game has its own Windows environment, its Proton prefix. Whatever you install here affects that one game, so there's nothing to break elsewhere.
  1. Download the redistributable

    Grab it from Microsoft's own page: Microsoft Visual C++ Redistributable downloads.

    Take X64 Redistributable for Visual Studio 2015-2022, saved as something like VC_redist.x64.exe. A game that shipped as 32-bit wants the X86 one instead, so if the x64 installer makes no difference, try that.

  2. Move the file into the game's folder

    Junk Store only lists what's in that folder, so the installer has to sit alongside the game:

    • Epic games, The Callisto Protocol for instance: ~/Games/epic/TheCallistoProtocol
    • GOG games: ~/Games/gog/your-game-folder
  3. Open the game in Junk Store

    Back in Game Mode, open Junk Store and go to the game's page.

  4. Open the sliders menu

    Press the button with the sliders icon, next to Play Game, to open the Actions menu.

    A game's page in the Junk Store Decky plugin showing Cardpocalypse, with the Play Game button and the sliders and cog buttons beside it
  5. Run the installer

    Choose Run exe in Game folder, at the top of the Actions menu.

    The Actions menu open, with Run exe in Game folder highlighted at the top, above Reset Launch Options, Uninstall Game, Update Game, Verify Game, Repair Game, Repair and Update Game and Enable EOS overlay

    That lists every executable in the game's folder. Pick the redistributable you just put there.

    The Select executable to run dialog listing the files found in the game folder: vcredist_x86.exe highlighted at the top, then UnityCrashHandler32.exe, install_deps.bat and Cardpocalypse.exe
  6. Work through the installer

    The installer behaves as it would on Windows. Accept the licence, let it finish, then launch the game.

If the game still won't start

  • Try a different Proton version. A runtime that installs cleanly under one Proton version can still fail under another. See checking and changing your Proton version.
  • Check ProtonDB. Other players note which Proton version a game wants, and any extra steps it needs.
  • Runs from Run exe but not from Play Game? That points at the launch options, not the runtime. Choose Reset Launch Options from the same Actions menu to put them back to default.

Stuck or need help?

Most issues are quick to sort out. Here's where to start.

Still stuck? Open a support ticket right in the Support Portal

For game-specific issues, feedback, or just a chat, you'll find us on:

Discord Reddit Lemmy

On Discord, head to the #decky-plugin-support channel.