All restored now, worked like a charm. Thank you very much! 

Thanks! The incident is recent, so I'll backup my Chrome profile for now. And thank you very much for Ctrl-S advice! Didn't figure it out myself, but really wanted manual backup to html feature.

Just deleted some important info only because trashbin icon for the closed group was on the same level as the safe close button for the several opened groups. Is there any way to restore that group from the backup? It was closed for a while, so chrome can not reopen it.