Steam Next Fest October 2026 Demo Upload Rejected - Missing Steam Input Default Config Metadata on Demo Branch - How to Fix

Problem: Your SteamPipe upload to the fest demo branch succeeds, but Steamworks shows STEAM_INPUT_DEFAULT_CONFIG_MISSING (or an equivalent metadata banner) and blocks the festival visibility toggle for Steam Next Fest October 2026. The default branch looks green; only the demo branch fails.

Who is affected now: Micro-studios promoting a fest_demo (or similarly named) branch in early September 2026 when the October fest submission window opened with a stricter metadata gate: Steam Input default config must be present on the branch players download during the fest, not only on default.

Fastest safe fix: Confirm the VDF and controller_base/ payload ship inside the demo depot → run a clean SteamPipe build that includes controller configs → regenerate library assets on the demo branch in Steamworks → leave fest visibility off until the metadata bar is green → add a CI matrix that runs the same metadata smoke on default and fest_demo.

Direct answer

The upload did not “fail”—the binary arrived without Steam Input default config metadata on that branch. Steamworks validates per-branch store metadata. If you built the demo from a preset that omitted controller files, promoted a depot without controller_base/, or never regenerated library assets after adding VDF, the portal correctly refuses to enable Next Fest visibility.

Why this issue spikes in October 2026

Next Fest October 2026 opened with demo-branch checks that were looser or manual in prior years—teams optimized default only.
Steam Input is now part of fest readiness alongside capsule and build stability—not only Deck Verified cert.
Branch promotion workflows often copy game binaries but not controller config folders from the main depot recipe.
Indie Slack channels report the same pattern: “upload OK, fest toggle red, main branch fine.”

This is metadata on the branch, not “controls dead on first launch.” If players have no bindings at runtime, see Steam Input default action set fails first launch. If glyphs fail Deck review, see Deck Verified Xbox Elite glyph fix.

Symptoms and search phrases

Steamworks: demo branch upload succeeded, fest participation toggle disabled with Input metadata error.
Error text or tooltip referencing default config, Steam Input, or controller configuration missing on demo only.
default branch: green metadata; fest_demo: red banner.
You promoted depots from an old build manifest that listed *.exe but not controller_base/.
Library thumbnail / controller config preview missing in Steamworks for demo build ID.

Root causes (check in order)

Demo depot recipe excludes VDF — separate ContentBuilder script or .vdf ignore rules.
*`controller_keys only ondefault` branch** in Steamworks — demo branch never received config assignment.
Partial depot promotion — binary updated, controller_base folder from previous build dropped.
Library assets not regenerated after adding Steam Input files to demo depot.
Wrong branch targeted — uploaded to internal QA branch, fest points at fest_demo without configs.
Runtime-only Steam Input — game uses API but never shipped published VDF in depot (metadata still missing).

Fastest safe fix path

Step 1 — Prove the demo depot contains controller files locally

On the machine that runs SteamPipe:

Open your demo build output folder (the tree uploaded to the demo depot).
Confirm a path equivalent to controller_base/ exists next to the game binary (layout varies by SDK; Unity/UE export templates differ).
Confirm at least one .vdf (or Steam Input exporter output) defines default_action_set → gameplay set name matches your code’s GetActionSetHandle string.

Success check: Zip the exact folder SteamPipe uploads; search inside for .vdf and controller_base.

Step 2 — Align demo and main Steam Input payloads

Copy the same steam_input/ (or project-specific) folder from the known-good main build.
Re-export from Steam Input Configurator if you bumped schema for autumn 2026 client refresh.
Commit the folder to the branch your fest_demo CI job builds—do not hand-copy only on one machine.

Success check: diff -r main vs demo controller trees shows no missing files before upload.

Step 3 — Clean SteamPipe promote including controller config

Bump build version in Steamworks (avoid reusing a build ID that lacked configs).
Run full ContentBuilder for the demo depot—no “binary only” incremental script unless logs prove controller files included.
Watch upload log for every file under controller_base/—not only Game.exe.

Alternative: If you use depot copy from main to demo in Steamworks, verify the copy job includes controller content set, not just the default install script slice.

Step 4 — Regenerate library assets on the demo branch

In Steamworks App Admin:

Select the demo branch (e.g. fest_demo).
Open Installs / Depots → confirm the new build ID is active.
Run Generate / Update library assets (wording varies by Steamworks UI revision) for that branch.
Wait for processing—metadata scans often lag binary upload by minutes.

Success check: Controller config preview or metadata subsection shows configured, not empty.

Step 5 — Re-test fest visibility toggle (off until green)

Leave Next Fest visibility disabled while metadata is red.
After Step 4 completes, refresh Steamworks—banner should clear.
Enable visibility only when no Input metadata warning remains.
Screenshot the green state for your BUILD_RECEIPT archive.

Step 6 — Deck and glyph spot-check (optional but cheap)

On Steam Deck with demo branch installed:

Cold launch from library (not loose EXE).
Confirm gameplay bindings work without opening Steam overlay.
Spot-check prompts against Unity glyph table tutorial if you use custom UI glyphs.

Metadata can pass while glyphs fail cert—different failure modes.

`steam_input_demo_metadata_receipt_v1.json`

{
  "schema": "steam_input_demo_metadata_receipt_v1",
  "fest": "steam_next_fest_october_2026",
  "branch": "fest_demo",
  "demo_depot_contains_controller_base": true,
  "vdf_default_action_set_present": true,
  "library_assets_regenerated": true,
  "metadata_banner_clear": true,
  "fest_visibility_enabled": true,
  "parity_diff_main_vs_demo_controller_tree": "identical",
  "captured_at_utc": "2026-05-24T00:00:00Z",
  "pass": true
}

Store beside your Wednesday smoke log. Set fest_visibility_enabled to false until metadata_banner_clear is true.

Verification checklist

Steamworks demo branch shows no Steam Input metadata error.
Fest visibility toggle enables without a blocking dialog.
Fresh install from Steam demo branch: controller works on first launch (runtime check).
controller_base path exists in uploaded depot manifest (build log archive).
Main and demo branches both pass the same automated metadata script (prevention below).

Prevention — CI matrix for `default` and `fest_demo`

Add a pre-promotion job:

Gate	Main	Demo
`controller_base/` present in artifact	required	required
`.vdf` contains `default_action_set`	required	required
File list hash matches main (or allowed diff doc)	baseline	must match
Library asset regen step documented	yes	yes

Pair with the curated checklist in 15 Free Steam Next Fest October 2026 Demo Metadata and Steam Input Checklist Resources.

Do not enable paid fest traffic from fest marketing cap until this receipt passes.

Troubleshooting

Symptom	Likely cause	Fix
Main green, demo red	Demo depot omitting VDF	Steps 1–3
Banner cleared, players no bindings	Runtime Init / ActivateActionSet	First launch action set help
Upload OK, banner persists 30+ min	Library assets not regenerated	Step 4
Only internal branch works	Fest points at wrong branch	Steamworks branch mapping
Playtest build OK, fest demo fail	Surfaces confused	Playtest vs fest isolation
Metadata OK, Deck glyph fail	Glyph lane	Elite glyph help

FAQ

Does every game need Steam Input for Next Fest?
Games without controller support may have different requirements. This article is for titles that use Steam Input VDF configs on PC builds. Confirm current Steamworks festival documentation for your app type.

Can I copy only the EXE to the demo depot?
That pattern causes this error. Ship the full install slice including controller_base/.

We use Unity Input System only—no Steam Input API.
You may still need published Steam Input configs for store metadata if Steamworks flags this gate. Input System alone does not populate Steamworks metadata—export and ship VDF per Steam Input docs.

Is this the same as Playtest invite builds?
No. Playtest uses different branches and depots. Keep playtest isolation so QA configs do not overwrite fest demo metadata.

How long after upload until the banner clears?
Often 5–30 minutes after library asset regeneration. Do not toggle fest visibility during processing.