Migration to V3: usb sdd drive wiped off!


I just did an update from v2 to v3. And my external usb drive Exfat ( samsung sdd 500G) has been wiped off.

Is it a known issue ? If yes, Don’t you think a hint about disconnect any USB drive before update would be smart ? Or am I the only one who don’t want to spend hours ripping litterally thousands of CDs again ?