Re: Cannot recover lost session on Mac!
Make sure you have Time Machine backups (or another recent backup)!!
quit your Opera browser
go to Library > Application Support,
find and delete 'com.operasoftware.Opera' folder,
open Time Machine, find a recent backup date before you've lost your tab session,
locate 'com.operasoftware.Opera' folder in that backup,
click on Restore,
re-launch your Opera browser.
Relax and smile now