In Thunderbird 31, the Nested Mail Lists are gone !

Question

I've changed from Netscape to Thunderbird 2 or 3 years ago. And the 2GB problem in folders size disappeared. And Thunderbird(2010-2011) worked perfectly using the same data profile as Netscape. I'm an openSUSE user, on a x86_64 workstation.
My address book uses for 10 years now **Nested Mailing Lists**.
In such a Lists I have 2 or 3 "SubLists", plus individual emails, etc.
after the last update to "Thunderbird 31" the address book **refuses all my nested lists**, saying, for example :
SubList <SubList> is not a valid e-mail address because it is not of the form user@host. You must correct it before sending the e-mail.
then I tested on a different nested list ans it's clear : NOW THUNDERBIRD REFUSES ANY SUBLIST IN A LIST
IT WORKED PERFECTLY TILL NOW

Answer 1

''Zenos [[#answer-666755|said]]''
<blockquote>
Always?
Fill in one address, press return. Does a To: button not appear in the next line down.
</blockquote>
Yes, the To: button does appear in the next line down, but that is not my question. Let me clarify.
On each addressee line, there is the identifier, To:, then there is a space to fill in the addressee's e-mail name and address. Between these two elements, in the previous version of Thunderbird, there was a small round symbol (I don't know what it would be called). Clicking on that symbol would select the entire addressee. That symbol is gone in the new version.