OMG I just looked and ALL my messages past 60 days ago are GONE! This is NOT ACCEPTABLE to me!

http://kb.mozillazine.org/Disappearing_mail

_I_ did not change any configurations. Your tinkering did. Quit!

I have it figured out and I got my messages back to visibility. But I will not be accepting any more updates to Thunderbird. The one just prior messed up my message format, which ONLY after the update defaulted to "Paragraph."

You figured out what, exactly?

The change in the paragraph spacing can be set back to its previous behaviour by unticking the checkbox at Tools|Options|Composition→General→"When using paragraph format…"

I figured out how the missing messages were being masked by the latest update. As for the "Paragraph" format, prior to the previous update, I had my "compose" settings set to "Body Text" before that happened. All of a sudden, someone decided it should be "Paragraph" and I had to change it back.

re :I figured out how the missing messages were being masked by the latest update.

What did you do to be able to see the missing messages?

Across the top of the message area, there are a series of symbols: a push-pin, something that looks like a pair of eyeglasses, a star and three more. I clicked on the eyeglasses symbol and everything was back as it should be. Hope it helps!

That toggles read/unread messages display. A standard feature that has been there since the year dot. Hover over it and you'll see a tooltip explaining its use.

Nothing to do with the update.

"Nothing to do with the update," huh? Then why did my messages disappear behind some pink stripes? And how is it they were visible again when I "just happened" to click on that icon?

I have my Thunderbird set not to receive any more updates, as I have had other negative issues with the tinkering in the past. Tinkering with one thing seems to make unwanted changes to other things. For each and every one of the past six "updates" I have had to spend time figuring out what setting has gone south and reset it to what _I_ want. "If it ain't broke, don't fix it."

It is a visible control put there for the convenience of users. It's not hidden, it doesn't require any special knowledge or "under the hood" stuff to make use of it.

I'm wondering why a seasoned user wouldn't know about this button and wouldn't be making daily use of it to ease their working.

You can't use tools to their best advantage if you don't bother to learn their capabilities.

The thing is, I thought my messages were gone. And I don't like having to take action because of someone else's tinkering.

I'm not sure what it is you do not understand - no one has tinkered with anything except you or whomever has access to your computer.

It is not a bug. It was not caused by an update. It is not a default setting. Nothing was lost. You had the Quick Filter Bar 'show only unread messages' option selected, which is a standard option that has been available for years. That option was selected by whomever was using Thunderbird. If you opened thunderbird and that option was already selected, then that is because it was selected prior to exiting and the info was stored in the session etc data.

The 'Quick filter Bar' has some really useful display options. Here is a link to Quick Filter Bar info:

• https://support.mozilla.org/en-US/kb/quick-filter-toolbar

And it can be made even more useful (IMHO) by use of this add-on:

https://addons.mozilla.org/en-US/thunderbird/addon/gmailui/

Once you have got the hang of regular expressions, you'll curse all the brain-dead searches offered in most software.