"Could not download file" is the error managers report most, and it is frustrating because the commissioner can usually download fine. That asymmetry is the clue: commissioner and manager downloads use different settings.
Work through these in order.
1. The credentials checkbox (most common)
In Game Settings → Online League → Online League Settings, there is a checkbox: "Save FTP account data for league file download in league file."
The OOTP manual states it plainly: if left unchecked, "human managers will be unable to download the league file via FTP."
The commissioner's own OOTP has the credentials stored locally, so uploads and downloads work for them. The league file handed to managers carries none, so every manager fails. Check the box, re-upload the league file, and have managers download again.
2. The yourdomain.com placeholder
OOTP ships with yourdomain.com in the League File URL field. If it is still
there, managers are being pointed at a domain that does not exist.
Replace it with the real URL. On SimHosts:
https://your-league.simhosts.com/leaguefile/
3. A stale accounts file
If a manager's connection worked and then stopped, the credentials changed
after their setup was created. The accounts file (accountsdata_gms.dat) they
have is out of date.
Symptom worth knowing: the file appears to load successfully but downloads still fail. Loading only reads the file — it does not validate the credentials.
Fix: the commissioner exports a fresh accounts file, or issues a new quick-start code.
Do not rotate credentials on a live league mid-season unless you plan to reissue accounts files to everyone. Every existing manager breaks at once.
4. The network blocks FTP
If a manager can download at home but not at work, school, or on hotel wifi, the network is almost certainly blocking FTP. Business firewalls routinely close outbound port 21 and the high passive port range.
There is no manager-side fix. The commissioner can solve it for everyone by switching to HTTP download — port 443 is essentially never blocked, and managers stop needing credentials at all.
5. Nothing was uploaded
Worth ruling out before debugging anything: run Online League Functions → Upload league files and confirm it succeeds. If the commissioner simmed but did not upload, there is genuinely nothing there to download. OOTP reports that as error -104, "file not found".
Narrowing it down fast
| Symptom | Most likely cause |
|---|---|
| Every manager fails, commissioner fine | Credentials checkbox (#1) |
| One manager fails, others fine | Their network (#4) or stale accounts file (#3) |
| Worked before, stopped suddenly | Credentials rotated (#3) |
| Works at home, fails at work | Network blocks FTP (#4) |
| Error -104 specifically | Nothing uploaded (#5) |
| Error -103 specifically | Wrong path — see error codes |
Preventing it
Switching league file downloads to HTTP eliminates causes 1, 3, and 4 outright — no credentials to distribute, nothing to go stale, and no blocked ports. Managers keep the in-game download button and you keep FTP only for team exports, where it is actually required.