I created a new Gmail account recently. While trying to add it to Thunderbird (45.6.0), i'm having the problem below. I have other Gmail accounts in Thunderbird (added a couple years ago), that are successfully getting mail. The problem is during addition of the new account to Thunderbird. The steps I'm following are: 1. Tools > Account Settings > Account Actions > Add Mail Account 2. Entered my name, the Gmail id, and my Gmail account password. 3. Clicked continue. 4. It says it found config in Mozilla db, choosing IMAP. 5. Clicked Done. 6. It says "checking password" and an unbadged window opens (a Thunderbird browser window?) with title "Enter credentials for <my id> on imap.gmail.com" 7. I entered id and pw. 8. Gmail responds, in that unbadged window: "Enable or disable cookies - If you’re trying to use your Google Account and see a message saying your browser's cookie functionality is turned off, it’s likely your browser's cookies are disabled. You’ll need to turn cookies on to use your Google Account." So, how do i enable cookies in the unbadged Thunderbird browser window? There is no toolbar and, for example, pressing Alt doesn't cause a toolbar or menu to appear. is that window even supposed to appear? or should it have been hidden from me, going between Thunderbird and Gmail, to check that the id/pw worked that I'd given Thunderbird? The same thing happens when i use an app pw for Gmail from this Windows 10 PC. How can i get past this, so i can access this new Gmail account on this PC? Thanks.