stablyai/orca · error · Error

Download session not found

Error message

Download session not found

What it means

Thrown by 'fs:appendDownloadedFileChunk' (src/main/ipc/filesystem.ts:785) when downloadSessions.get(transferId) returns undefined. Download sessions live in an in-memory Map keyed by transferId; they are created by fs:startDownloadedFile and removed by fs:finishDownloadedFile, fs:cancelDownloadedFile, a 30-minute TTL cleanup timer (DOWNLOAD_SESSION_TTL_MS), or cleanupDownloadSessionsForSender when the owning webContents is destroyed.

Source

Thrown at src/main/ipc/filesystem.ts:785

        return { canceled: false, transferId, destinationPath }
      } catch (error) {
        await cleanupLocalTransferPath(tempPath)
        throw error
      }
    }
  )

  ipcMain.handle(
    'fs:appendDownloadedFileChunk',
    async (
      _event,
      args: { transferId?: string; contentBase64?: string }
    ): Promise<{ ok: true }> => {
      const transferId = validateRequiredString(args?.transferId, 'transferId')
      const contentBase64 = validateRequiredString(args?.contentBase64, 'contentBase64')
      const session = downloadSessions.get(transferId)
      if (!session) {
        throw new Error('Download session not found')
      }
      await session.handle.writeFile(Buffer.from(contentBase64, 'base64'))
      return { ok: true }
    }
  )

  ipcMain.handle(
    'fs:finishDownloadedFile',
    async (
      _event,
      args: { transferId?: string }
    ): Promise<{ canceled: false; destinationPath: string }> => {
      const transferId = validateRequiredString(args?.transferId, 'transferId')
      const session = await closeDownloadSession(transferId, false)
      if (!session) {
        throw new Error('Download session not found')
      }
      let promoted = false

View on GitHub (pinned to 1136503c6a)

Solutions

  1. Restart the download via fs:startDownloadedFile to obtain a fresh transferId, then re-stream the file.
  2. Ensure the full append sequence completes within the 30-minute TTL and before the owning window closes.
  3. Confirm the transferId matches the most recent start response and that the same webContents issued it.

Example fix

// before: appending after the session was finished/expired
await invoke('fs:appendDownloadedFileChunk', { transferId: staleId, contentBase64 })

// after: restart on session-not-found, then continue
try { await invoke('fs:appendDownloadedFileChunk', { transferId, contentBase64 }) }
catch (e) {
  if (/session not found/.test(e.message)) {
    const r = await invoke('fs:startDownloadedFile', { suggestedName })
    transferId = r.transferId
  } else throw e
}
Defensive patterns

Strategy: validation

Validate before calling

// Track transfer lifecycle in the renderer; treat append as valid only while 'active'.
function canAppend(t: { id: string; state: 'active' | 'done' | 'canceled' }): boolean {
  return t.state === 'active'
}

Try / catch

try {
  await invoke('fs:appendDownloadedFileChunk', { transferId, contentBase64 })
} catch (e) {
  if (e instanceof Error && /session not found/.test(e.message)) {
    // restart: fs:startDownloadedFile -> new transferId -> re-stream from the beginning
  } else throw e
}

Prevention

When it happens

Trigger: An append chunk arriving for a transferId whose session was already closed: finish/cancel ran first, the 30-min TTL timer fired, the sender window was destroyed/reloaded, or the transferId was never started or belongs to a different sender.

Common situations: Very large or paused transfers exceeding the 30-minute TTL; renderer resuming a download after the window closed and reopened; a double-finish/cancel race; stale transferId held across an SSH reconnect that tore down app state.

Related errors

AI-assisted analysis of stablyai/orca@1136503c6a (2026-08-12). Data as JSON: /api/errors/afc73d9b4ffe3bf2. Report an issue: GitHub.