Il est maintenant possible de définir un carnet d'adresses par défaut qui sera sélectionné lors de l'ouverture des carnets d'adresses. Pour définir la valeur par défaut, cliquez avec le bouton droit sur un dossier et sélectionnez l' entrée du répertoire de démarrage par défaut dans le menu affiché. J'espère que cette réponse à été utile !!!

Does your missing address book have a period or some other non-alphabetic character in the name?

I don't know. I am not not smart with these kinds of things. I wish I could talk to someone. I entered a new membership address book, 2 actually (I needed to use it). Both they are working fine. It is all the addresses I had prior to the update that are missing.One thing I just thought of is in that I may have inadvertently asked for a new install and not an update. I've used Thunderbird for years and supported it as well. If there is anyway you could have me call a phone number and talk to a life person I would greatly appreciate that. Thank you. Joe L