Yes, thanks. Since the upgrade to FF 58 everything is ok again with Speed Dial.

In between I upgraded to Firefox 58. And since this time the backup dialog from above appears again and so now I can also backup to a file again. Strange why this did not work with ff 57 before.

Rainer

The "How do you want to backup" dialog shown in your post does not appear when I click on "Backup Dials". Thats the problem. When I click on "Backup Dials" simply nothing happens, I only see a optical feedback of the button showing me that I really clicked it.