Windows Defender Blocking LUMIX Tether — Whitelist Fix

This is a focused fix for one specific LUMIX Tether problem: Windows Defender Blocking LUMIX Tether. Walk the list top-to-bottom — the first item is the most common cause in support tickets.

Root causes, in order of frequency

1. SmartScreen unsigned installer warning
2. Click "More info → Run anyway"
3. Add the install folder to Defender exclusions
4. Re-verify SHA-256 on this site

Confirm the fix

After each step, close LUMIX Tether completely, unplug USB for 5 seconds, replug and relaunch. The connection state is cached — without a full power-cycle of the link you cannot tell which fix worked.

Still stuck?

If none of the above resolved it, swap the cable for a known-good USB 3.2 Gen 2 cable (this fixes ~40% of remaining cases) and reinstall LUMIX Tether v2.12 from the Windows 11 install guide. Related: troubleshooting guide. complete LUMIX Tether guide.