Some more information: I wondered if the Apple app-specific P/W might be involved, so I reset the password. No change in the behavior. I see the subject line of incoming messages, but get the error on clicking the line. The body of the message does not appear.

For poor reasons, I tried repairing the inbox. The result was a long wait, and now every message in the inbox shows this same behavior: click on the item and get the error message (which appears as a pop-up from the tool tray, at right).

So, Thunderbird is now completely disabled for this account.

There's another user reporting the same problem. https://support.mozilla.org/en-US/questions/1170254

That makes it unlikely the problem is with Thunderbird. You should talk to Apple.

The problem resolved itself over night. This is consistent with it having been an Apple problem.

Thanks for your response, and the pointer to the other report.

Dick

The problem is back, on and off. Yesterday, it affected a few messages, then disappeared. This morning, it’s back in force. The mail on the server is fine, accessible from iPhone and Apple’s iCloud Web interface. I will contact Apple.

Dick

apple claimed it wasn't their problem; i deleted and then reconfigured my mac mail account on thunderbird 52.2.1. it was some hassle because i had to undo and then redo the apple two-step authentication for outgoing and incoming imap passwords. after it was reinstalled, it worked fine ... for a half-hour. now back to the same old same old. i now believe it's a problem with apple and encourage the mozilla support to contact before the issue becomes widespread.

The problem is intermittent and still present as of 8/8/17 11:06 PM PST. And imho it is a thunderbird problem not apple. reason: I am able to get my apple mail using windows live mail - no problem. iphone - no problem. icloud.com /mail - no problem. So this is particular to thunderbird. am i wrong? mozilla techies are you listening??

Hi, I too am having the same problem and my bird is version 31.3.0, running on Mac OX X el Capitan 10.11.6. I contacted Apple support for possible solution or insight, but they had nothing at the moment. I tried following, and nothing worked;

• delete and reconfigure mac.com mail
• delete mac.com email account through tbird account menu, then manually delete the particular imap profile folder and reconfigure it
• create a new admin account on MacOSX, login to the new admin account and create mac.com mail

Now I suspect apple has done something to their imap setting on August 4 and that something affects us all. Thanks.

Ryosuke

A question: if the problem source is apple changing its IMAP settings, why does windows live mail still work fine on my pc and only thunderbird is having a problem? (if apple changed the settings for non-apple email clients, shouldn't it affect all non apple client software?)

from the other message thread: see below > i agree with altv >> it's thunderbird that is the problem.

"I have tried so hard to get TB to work in conjunction with App specific password on a Windows 7 laptop but it has been a complete and utter waste of time. It will not work and I uninstalled Thunderbird and have gone back to using M/S Outlook. At least that allows me to get emails from all my addresses using the App specific passwords. The Server settings are the same as those used in TB. The problem must rest with TB on that basis. Sorry, Thunderbird, but if it takes more than 24hours to try and set the thing up it ain't worth it! Cheers altv "

Here's what I posted last night on the other forum discussion about this same subject (https://support.mozilla.org/en-US/questions/1170254#answer-994740):

Well, blow me down! I just now looked at my emails and I can read every one of them.

Whoever and however, thank you very much (and I hope I haven't spoken too soon — we'll see)!

And here's what I just posted there this morning:

I spoke too soon.  :( All the new emails I just received this morning are blank (although all the ones that came back last night are still visible).

Oh well. Back to square 1.

And here's what I posted on the other forum a couple of hours before posting Well, blow me down!:

I wonder if I might have stumbled on a couple of possible clues as to what the problem is.

The first possible clue is that I've noticed that among all the blank messages I've received since the problem first showed itself (Aug. 7 at 6:38 PM EST) I can actually view the content of a few of the messages. However, (and here's the possible clue) I can only see those contents if I have selected the "Message body as plain text" option under the View menu. In other words, the contents of those few emails are invisible if either the "Original HTML" or "Simple HTML" option is selected.

The second possible (and more telling) clue is that in Apple's own Mail apps on my iPad, on my MacBook Pro and on my iCloud webpage, I can see the contents of all the emails that appear blank in Thunderbird. That seems on the face of it to point the finger at Thunderbird and not Apple.

By the way, how do we know if anyone from Mozilla is working on this problem or has even seen it? Do we assume they are aware of it and hopefully working on a solution, or do we wait for them to post a "we're working on it" message?

I have no idea if mozilla has a clue. i've gone back to using windows live mail 2012 on my windows 7 PC and it is working fine while thunderbird continues to generate the UID error this morning.

In the interim I can see my emails fine on Apple's Mail apps, but it's too bad Thunderbird is misfiring. I really prefer it over Mail. It has more features and for me it's just a lot handier.

I agree that I don't really like windows live mail either but thunderbird is unstable/buggy - the recurring issue where it occasionally won't copy a sent message to the sent folder (has been an issue for months) and now this issue which makes it totally unusable. I looked for a thunderbird/mozilla support phone number where i could contact someone but there are no contact numbers. That's what happens when you use a free product i guess.

there is no one to contact at mozilla; it's an open source enterprise allegedly devoted to quality. one can only hope that this issue gets the attention of someone competent enough to offer a resolution. we have no idea how many complaints of this type are currently circulating , but in my search for this thread i found similar problems dating back to 2012. this is the first problem i've had with any mozila software in 20 years. my next step here will be google the issue. maybe there are other ideas out there.

For anyone still seeing the problem, please provide logging information. https://wiki.mozilla.org/MailNews:Logging

thanks for the logging information link though i for one will need step by step instructions on how to create the logging information. i read the link above but it's not clear to me how to do it.

Yeah, those instructions are a bit "rich" for my limited under-the-hood knowledge. Might there be step-by-step logging instructions for Dummies? And a plain-language explanation of how the information will be used would be very much appreciated.

The problem comes and goes, on its own, with no changes in setup in Thunderbird or the Apple server. Today it’s working, but I have no confidence the problem is resolved.