Error code

Steam 105

STEAM105
Game/Platform Error· An error code shown by a game or gaming platform/launcher.

What it means

Steam cannot load the store or community pages — displays "Unable to connect to server"..

How to fix it

  1. Flush DNS cache (ipconfig /flushdns).
  2. Switch to a public DNS server such as Google DNS (8.8.8.8 / 8.8.4.4).
  3. Clear Steam's web browser cache in Steam > Settings > Web Browser.
  4. Disable any ad-blocker extensions.
  5. Disable VPN if active.
  6. Check Steam server status at steamstat.us.
  7. Restart your router.

Not affiliated with Steam. Answer summarized from the manufacturer's manual linked above; consult that source for the authoritative procedure.