New info: when I first start Firefox, I see my icon (has a picture of me) upper right corner that indicates I'm logged into Firefox. Shortly after the browser starts, I am prompted for my "master" password which normally happens, but when I login with this master password, my icon goes away and the yellow triangle with exclamation mark appears, indicating that I need to sync or something. When I click on the 3 horizontal lines upper right corner, top of the drop down menu says "Reconnect to Sync". what is going on here?

one more thing: clicking on my icon (picture of me upper right corner of browser) the drop down menu says, "Check your Email. You'll need to verify your account before you can sync". what email? I dont have anything in my inbox to check. what is this thing talking about? See picture attached.

See:

• https://support.mozilla.org/en-US/kb/forum-response-firefox-sync-verification-email-faq

I was using my email client https://outlook.live.com. I dont know about getting any emails or even if it matters. when I start firefox on either machine, I am automatically logged in as is evident by my little icon in the upper right hand corner and clicking on it, at the top of the drop down menu, it says I am logged in. both machines say that. my primary machine has all the bookmarks, saved logins, and other settings, along with my home page just the way I want it. The secondary machine that I just loaded Ubuntu on, has firefox, also. When I start firefox on the secondary machine, it automatically logs me in, just like the primary machine. however, there are no saved bookmarks or logins etc... as though it has never synced. If I click on my icon where it says I'm logged in and the bottom of that drop down menu I click "Sync Now" and I'm prompted to login, but at the same time it logs me out and even after I put my email address and password in and login and it says I'm logged in, in the body of the web page, I get the yellow triangle from hell which indicates I'm logged out. This occurs on both machines. I do get a brief message that says its syncing, but that goes away. subsequent login attempts will briefly show the icon with my picture in the upper right hand corner (for 1 second) and then it goes away and I get the yellow triangle again. none of what the help link you sent me addressed these problems. what now?

The other thing I noticed is when I start Firefox, it opens and I am automatically logged in. After a couple seconds, another dialogue box opens up to prompt me for my "Master Password". When I enter my password, I am logged out. that happens every time.

new discovery: I just read cor-el's link again and found that when I click the "sync now", my icon gets a little envelope on it and the message says, check your email" however, I am not getting ANY emails. does this mean that my account is locked?

ooops! Actually, I do get an email. but its only when signing in and it just says "New sign in to firefox" with ip address and a big blue button that says "manage account" . I click on that button and another page opens, but there is nothing to send back to my account or firefox browser to tell it that I'm the one signed in. I guess I'm missing the boat on this stuff. is there supposed to be a different email that I get when I sync?

We ended up debugging this in a private bugzilla bug, and tracked it back to a subtle issue in Firefox Accounts and its 'recovery key' feature: https://github.com/mozilla/fxa/issues/2106

Unfortunately the only resolution was to delete and re-create the account, but at least we've found the bug and can hopefully avoid other users hitting this problem.

I don't believe I have the ability to close this thread, and the original poster can't sign back in because they deleted their Firefox Account, but I think it's safe to consider it resolved.