Fix Steam Workshop Download Failed or Stuck at 0 Bytes (2026)

What is the Steam Workshop Download Failed Error?

Steam Workshop downloads can fail in three distinct ways: a "Download Failed" notification appears in the Downloads queue, an item shows "Subscribed" but never enters the queue at all, or the download starts and freezes at 0 B / 0 B with no progress. Each pattern has a different root cause. The Workshop uses a separate download pipeline from regular game files — it relies on per-game appworkshop_<appid>.acf manifest files that track subscribed items, and any mismatch between that manifest and the cloud subscription state stalls everything.

When does it occur?

• Subscribing to many Workshop items in rapid succession (rate-limit triggers)
• After Steam restart when the previous session had a half-finished workshop download
• On games with very large Workshop libraries (Garry's Mod, Skyrim, Cities Skylines 2, ARMA 3)
• After moving a game library to a new SSD or external drive
• When the Steam content servers in your region are degraded
• On a fresh Steam install before the first Workshop sync completes

Common causes

• Corrupted appworkshop_<appid>.acf file — the manifest Steam reads to know what's subscribed
• Subscription state out of sync between Steam servers and local client (the "subscribed but no queue" case)
• Steam download cache poisoned with a partial download from a previous session
• CDN/region mismatch sending you to a degraded content server
• Disk write permission denied on steamapps/workshop/content/<appid>/
• Family Sharing or library on an external drive that isn't writable by Steam process
• IPv6 routing to Steam CDN failing while IPv4 works (common with some ISPs)
• Antivirus locking files in steamapps/workshop/downloads/

Three failure modes, three fix paths

Failure mode A — "Subscribed but never queues" → subscription-sync issue. Local ACF doesn't reflect cloud subscription. Go to fixes 1, 2.

Failure mode B — "Queues, then Download Failed" → CDN / network / disk issue. Go to fixes 3, 4, 5, 7.

Failure mode C — "Stuck at 0 B / 0 B" → cache corruption or permission issue. Go to fixes 4, 6, 8.

Step-by-step fixes

1. Force resubscribe via the Workshop URL — unsubscribe in Steam, fully close Steam (tray icon > Exit), then go to the item's Workshop page in a browser, sign in, and click Subscribe again. This rewrites the cloud-side state cleanly.
2. Delete and rebuild the appworkshop_<appid>.acf file — close Steam, navigate to Steam\\steamapps\\workshop\\ (default C:\\Program Files (x86)\\Steam\\steamapps\\workshop\\). Delete appworkshop_<appid>.acf where <appid> matches the game (e.g., appworkshop_4000.acf for Garry's Mod, appworkshop_730.acf for CS2, appworkshop_949230.acf for Cities Skylines 2). Relaunch Steam — it will regenerate the file from your cloud subscriptions on next sync.
3. Clear Steam download cache — Steam > Settings > Downloads > Clear Download Cache. Steam logs you out; sign back in. This wipes corrupted partial-download state without touching installed files.
4. Delete the partial download folder — close Steam, delete Steam\\steamapps\\workshop\\downloads\\<appid>\\ entirely (this only contains in-flight downloads, not installed mods). Restart Steam to re-queue cleanly.
5. Change download region — Steam > Settings > Downloads > Download Region. Pick a different city geographically close to you (not necessarily the closest — try the second-nearest if the closest is failing). Restart Steam.
6. Verify write permissions on the workshop folder — right-click steamapps\\workshop\\, Properties > Security, ensure your user has Full Control. If on an external drive, confirm it isn't read-only or in "ready for safe removal" state.
7. Disable IPv6 temporarily for the download — Network Adapter Properties > uncheck Internet Protocol Version 6 (TCP/IPv6), restart Steam. Re-enable after the download completes. This is the actual fix for the "queue jumps to Download Failed in 0.5 seconds" symptom that no one explains.
8. Whitelist Steam in antivirus — add Steam.exe and steamapps\\workshop\\ to the exclusion list. Windows Defender Real-time Protection sometimes locks the file while Steam tries to write.

The appworkshop ACF repair (advanced)

When item count is wrong or specific items refuse to download:

1. Close Steam completely (tray icon > Exit, then check Task Manager for steam.exe)
2. Open appworkshop_<appid>.acf in a text editor (Notepad++, VS Code)
3. The file is a Valve KeyValue format. Look at the WorkshopItemsInstalled and WorkshopItemDetails blocks
4. If a specific item is stuck, find its ID in the WorkshopItemDetails block and delete that single entry
5. Save the file and restart Steam — Steam will re-evaluate that item and re-download it
6. If unsure, just delete the entire file and let Steam rebuild it (per fix #2)

If it still doesn't work

Use SteamCMD as a fallback download path: install SteamCMD, run steamcmd +login <username> +workshop_download_item <appid> <workshopid> +quit. This bypasses the Steam client's manifest layer entirely and writes the item directly to your Steam content folder. For Garry's Mod and Skyrim, also check the dedicated subreddits (r/gmod, r/skyrimmods) for game-specific mod loader interactions — some mods require third-party managers (Mod Organizer 2, Vortex) that intercept the workshop pipeline. If the failure is recent and affects multiple games at once, check steamstat.us — Steam CDN incidents typically resolve within 2-6 hours and no client-side fix will work during an outage.