Too many upload completions
POST /api/upload/complete (desktop multipart finalize) was rate-limited for this user/IP. Default is about 300 completions/hour (shared with related cancel traffic).
Why this happens
Each finished file calls complete once. Huge batches, aggressive retries, or scripts can exhaust the hourly cap even when parts uploaded fine. Member API complete may show a more generic “Too many uploads” message instead.
Diagnose and fix
1. Member: wait for the window to reset; avoid hammering retry on the same completes.
2. Admin → Settings → Mods → Upload completions rate (upload_source_file_complete_rate_per_hour).
3. Related knobs: upload starts rate, chunk parts rate — raise only what you need.
4. Reload nginx limit config if your deploy ties Mods rates to gateway limits.