openclaw - 💡(How to fix) Fix Windows: Telegram media download fails with EPERM on FileHandle.sync() [1 comments, 2 participants]

Summary

On Windows, inbound Telegram media can fail to download/save with EPERM: operation not permitted, fsync. The bot then sends Failed to download media. Please try again. even though Telegram delivered the file.

Environment

• OpenClaw: 2026.5.3-1
• OS: Windows 11 / win32
• Channel: Telegram polling provider
• Node runtime used by gateway: Node 22.22.2 bundled runtime

Observed behavior

After sending an image to the Telegram bot, OpenClaw logs:

media fetch failed
Error: EPERM: operation not permitted, fsync

The user-facing Telegram reply was:

Failed to download media. Please try again.

Likely cause

In the built package, writeSavedMediaBuffer writes a temp media file, opens it, calls FileHandle.sync(), closes it, then renames. On Windows this sync() call can throw EPERM, even when the file write itself is otherwise fine.

Observed in installed dist file around:

dist/store-D8lbL3Fm.js
writeSavedMediaBuffer(...)

Local workaround tested

Catching Windows-only EPERM around handle.sync() allowed media saving to succeed:

try {
  await handle.sync();
} catch (err) {
  if (process.platform !== "win32" || err?.code !== "EPERM") throw err;
} finally {
  await handle.close();
}

After this local patch, the same media save function successfully wrote inbound images to .openclaw/media/inbound.

Expected behavior

Windows should not fail Telegram media ingestion solely because FileHandle.sync() returns EPERM. OpenClaw should either tolerate this Windows-specific sync failure or use a Windows-safe fsync strategy.