When the crane jams
Error database: exact symptom → real cause → what actually fixes it. Built from the issue tracker, the discussions board and my own bruises.
Manifest, license & login errors
Most 'it won't download' problems land here: a 401 on an old manifest, a depot your account is refused, a login that won't take. These are policy and account errors, not bugs — and each has a specific, fixable cause I walk through in order.
Can you still download old versions?
The running log of Valve's manifest restrictions: what works, what returns 401, the full timeline since 2021 — with a status banner I update after every re-test.
check the status → errors"No manifest request code was returned"
The full diagnostic tree for the 401: anonymous vs account, branch checks, gated old manifests, ID mix-ups — what to try, in which order, and what's a waste of an evening.
read the diagnostic → errors"Not available from this account"
Why Steam refuses depot keys for games you're sure you own: family sharing, the anonymous inversion, DLC depots, regional packages, vanished licenses.
read the diagnostic → errorsLogin & Steam Guard errors
InvalidPassword with a correct password, AccountLogonDenied, RateLimitExceeded, TwoFactorCodeMismatch, dead tokens — the full decoder table.
read the diagnostic →Network, CDN & speed
When the bytes themselves are the problem. Timeouts, SSL errors, a crawl where you expected a flood — these separate CDN weather from your own firewall, and show which knobs actually move the needle.
Timeouts, SSL & missing chunks
Which network errors are CDN weather and which are your firewall — plus -cellid, -max-downloads tuning, ISP throttling honesty and the chunk that's truly gone.
read the diagnostic → performanceIt downloads, but slowly
Why DepotDownloader crawls where the Steam client flies — tuning -max-downloads and -max-servers, the -cellid region trick, why old builds are slow by nature, and ISP/disk bottlenecks.
read the diagnostic →Won't start, crashes & broken downloads
The tool quits before it finishes, throws a wall of red text, or hands you broken files. Here's how to tell a real crash from a deliberate error message, and the disk-and-environment causes behind most of them.
It won't even start
The .NET error you shouldn't be seeing, chmod after unzipping, macOS quarantine, the Windows flash-and-vanish, SmartScreen and non-ASCII paths.
read the diagnostic → errorsExceptions & hard crashes
NullReferenceException, OverflowException, IOException, the CET startup assert — and the one-line test for telling a real bug from a deliberate "Error:" message you can fix in five seconds.
read the diagnostic → diskIt stalls, or comes back wrong
Frozen on "Pre-allocating", "Couldn't find any depots", a mid-download freeze or broken files — the disk-and-filter failures, and the -validate repair that fixes a corrupt download without starting over.
read the diagnostic →After the download
You got the files — and the game still launches the latest version anyway. The one diagnostic for the most common 'my downgrade didn't work' complaint, and how to make the old build stick.