what security exception? Acknowledged it how?

Matt, Used to acknowledging them so I paid little attention ... I know. They must be logged somewhere but I have had no luck finding them. Error Console is no help in locating them.

So, I downloaded the last version that worked, 38.5.1, installed and deleted/recreated one of my accounts - yahoo.com. This required that I use the imap and not the pop setting. Unfortunately my other accounts use pop and I have not been able to configure them yet - switched back to the dark side and MS email for one of my accounts just so I could receive the confirmation email sent by this forum - HINT: when the issue is email please provide an alternative confirmation mechanism. "when system is down read the online manual..."

Thanks for the help

Error Console:

Timestamp: 2/18/2016 7:44:23 AM Error: path is null Source File: resource://gre/modules/osfile/ospath_win.jsm Line: 220 Timestamp: 2/18/2016 7:43:58 AM

Error: downloadable font: kern: Too large subtable., table discarded (font-family: "Open Sans" style:normal weight:normal stretch:normal src index:1) source: https://www.mozilla.org/media/fonts/OpenSans-Regular-webfont.2696e36f12c5.woff Source File: https://www.mozilla.org/media/css/thunderbird-start-bundle.08a09d25e7a1.css Line: 1, Column: 1057 Source Code: @font-face { font-family: "Open Sans"; font-style: normal; font-weight: normal; src: url("/media/fonts/OpenSans-Regular-webfont.83efe33660ab.eot?#iefix") format("embedded-opentype"), url("/media/fonts/OpenSans-Regular-webfont.2696e36f12c5.woff") format("woff"), url("/media/fonts/OpenSans-Regular-webfont.3cbf4d3ed22e.ttf") format("truetype"); }

Timestamp: 2/18/2016 7:43:58 AM Error: downloadable font: kern: Too large subtable., table discarded (font-family: "Open Sans Light" style:normal weight:normal stretch:normal src index:1) source: https://www.mozilla.org/media/fonts/OpenSans-Light-webfont.1c8075cacedb.woff Source File: https://www.mozilla.org/media/css/thunderbird-start-bundle.08a09d25e7a1.css Line: 1, Column: 36 Source Code: @font-face { font-family: "Open Sans Light"; font-style: normal; font-weight: normal; src: url("/media/fonts/OpenSans-Light-webfont.804037562eab.eot?#iefix") format("embedded-opentype"), url("/media/fonts/OpenSans-Light-webfont.1c8075cacedb.woff") format("woff"), url("/media/fonts/OpenSans-Light-webfont.ecb4572a5e47.ttf") format("truetype"); }

my guess is the exception was raised by your anti virus and now it is blocking the new version. There is also something radically wrong if you have to use POP. Yahoo supports IMAP and Thunderbird knows it. For it not to work, again I look to your anti virus. Especially Norton's which is incapable of scanning IMAP accounts, or pop accounts using SSL or TLS connection security., but does a good job of messing up the new account wizard.

I'll try turning off Norton security suite and attempt to upgrade / retrieve mail - now even 38.5.1 doesn't work...

I turned off norton, deleted all certificates related to yahoo, google, ... mail accounts. Installed the 38.6.0 upgrade and received the security exception attached. I did not add a security exception and was unable to retrieve email.

I can send without issue

Why on earth would you delete any certificates? That is simply asking for trouble. Lots of it. The chain of trust that is contained in the certificate store is the basis of SSL. Each entry has been carefully considered and the legitimacy of the institutions checked. Under no circumstances s removing certificate of any purpose other than to mess up a working system.

I think your best bet is reinstall Thunderbird.  Even then we might have to manually fix your certificate store.

Yes, removing certs is a bad thing. My thought was that by removing the certs associated with comcast, secureserver, yahoo, gmail, they would be forced into a reload situation. Which seems to have worked because I could then obtain the cert error attached to my previous response which you asked for. So far now with 38.6 reinstalled the imap settings for gmail and yahoo are working for send and retrieve but pop receive is not working. Have looked at the comcast imap config but it's not working,

Well, pop seems to be dead. I found more recent comcast imap config info and can send/rcv using imap which is unfortunate because I don't care about "multiple device synchroization" as advertised. Now I just need to find the secureserver.net imap config and should be set.

What forced this "upgrade" to imap?

Thanks for your assistance

Any chance there's a way to migrate my pop profile so I can retain my message filters, folder locations, ... ?

There is no forced upgrade. I am using V47 as a nightly developer build with more pop accounts than IMAP. I really dislike Googles IMAP.

But lets talk facts.

Norton can scan email on non SSL secured POP accounts. It can not scan mail on SSL secures connections or IMAP accounts. This is from the Norton support site.

You are able to work with the mail protocols Norton simply can not work with. IMAP. your SSL secured POP account died

Therefore I think your copy of Norton's is broken in some way. it may be so fundamental that only a complete uninstall will fix it.

Manual copy of the msgfilter.dat. Copy the folder structure from the original pop account and minimal rules editing... could have been worse but shouldn't have trashed my pop mail with no back out IMO. Odd that suddenly with 38.6, norton and pop die. Welcome to your choice of email protocol; will that be imap or imap?

Thanks Matt!