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A website added as exception is deleted next time Firefox is used. Cannot find any solution. Can turn off ETP manually via shield symbol in url bar.

Edition Windows 10 Pro Version 22H2 Installed on 30/10/2024 OS Build 19045.6466 157.0 Firefox Release

Hello,

I urgently need technical assistance with a serious issue involving Mozilla Thunderbird and my professional certified email account (Aruba PEC, Italy).

I have been using Thunderbird to manage my professional email correspondence for several years.

I organize processed emails into yearly folders (2024, 2025, 2026, etc.), located under my email account in Thunderbird, not under Local Folders.

Today, October 13, 2026, I discovered that all emails dated January through September 2026 have disappeared from my "2026" folder.

Only emails from October 2026 remain.

The missing messages include professional correspondence, certified email delivery receipts, acceptance receipts, and potentially legally significant communications.

What I have verified so far:

The "2026" folder exists both in Thunderbird and in Aruba Webmail.

Both display the same remaining emails from October.

The Trash folder is empty.

The 2024 and 2025 folders still contain their messages.

Thunderbird's retention settings are configured to "Don't delete any messages."

The "2026" folder inherits the account's retention settings.

I did not knowingly delete or move these messages.

Aruba customer support informed me that they cannot restore the missing emails.

I checked Windows Previous Versions and OneDrive, but no backup was found.

I located the local Thunderbird mailbox file named "2026" in the profile's ImapMail directory. It is approximately 3 MB.

Inspection of a copy of this file did not reveal message headers from before October 2026.

I could not find another larger copy of this mailbox file in the Thunderbird profile.

I occasionally remove unused folders under "Local Folders", but I do not recall deleting any folder containing these messages. The affected "2026" folder is located under the IMAP email account.

My questions are:

Could Thunderbird have deleted or moved these messages automatically despite the retention settings?

Could IMAP synchronization, folder corruption, message filters, or compaction explain this situation?

Are there any additional Thunderbird files, caches, databases, or recovery methods worth investigating?

Is there any way to identify when or how the messages were deleted?

What steps should I take to prevent further data loss?

I have preserved a backup copy of my Thunderbird profile and would prefer not to perform potentially destructive operations.

This is particularly serious because the missing messages are part of my professional and legally relevant correspondence.

Any technical guidance would be greatly appreciated.

Thank you very much for your help.

Quick breakdown: I had my old boss's email loaded in Thunderbird for a short while Didn't want to be invasive after project ended Removed profile from Thunderbird Then Shaw and Rogers Merged - Sold email service too 3rd party Easy-On-Net Easy On Net dropped the ball and all of the historic folders and contents were lost when Shaw/Rogers severed their connection Can I recover up until the point I disconnected his old profile?

My system • Windows 11 on a Dell laptop. • Firefox Version 157, my default browser. • Norton 360 Standard. • Two Firefox profiles; the warning appears in both. • Firefox Troubleshooting Mode does not eliminate the warning https://support.mozilla.org/en-US/kb/sslkeylogfile-warning?utm_source=chatgpt.com

What I have observed The warning appears on Firefox network-error pages, including when the internet is disconnected or I enter an incorrect URL. A particularly reproducible example occurs after I successfully log in to Kotak Net Banking and select Help → Raise a Query. Firefox then displays a connection/privacy warning associated with the embedded page. I do not see the same behaviour in Chrome or Firefox Private Browsing when performing the equivalent Kotak steps. Troubleshooting already completed 1. Norton Safe Web HTTPS scanning was disabled and re-enabled without resolving the issue. 2. QUIC/HTTP3 scanning, WebSocket Protocol Scanning and DNS/DoH scanning were individually tested without resolving it. 3. Firefox Enterprise Policies are inactive. 4. I found no SSLKEYLOGFILE entry in either Windows User Variables or System Variables. 5. Norton and Dell malware scans found no malware. 6. The warning also occurs when I connect through a mobile phone hotspot rather than my usual BSNL connection. Questions for Mozilla's technical contributors 1. Does this warning establish that Firefox detects SSLKEYLOGFILE, or could another mechanism produce the same message? 2. Can the variable be inherited by Firefox from a parent process or injected into its running process even when it is absent from the Windows User and System Variables? 3. What is the safest way to identify which process or security product is setting it on Windows 11? 4. Is there a known interaction between Firefox 157 and Norton 360 Standard that could explain this behaviour? 5. What evidence should I collect to distinguish a Norton issue from a Firefox issue without disabling security protections or modifying Windows settings? I am not looking to disable security features indiscriminately. I want to identify the actual cause and, if Norton is responsible, determine the precise setting that needs attention. I would particularly appreciate a response from a contributor with Windows networking, Firefox TLS or security-software diagnostic experience. Thank you.

As of Oct 12 2026 I also have this issue. About a week before the 12th I was getting messages that I needed to sign into my RCN account which I would do and it just kept asking me. A few times each night to start then right before it shut me out I had over 50 of these messages just flooding my screen. I never did get a screen shot of that message, but did for the 2 error messages I got later once it shut me out.

I shut down my computer the night of the 11th then when I signed back in on the 12th I could not send or recieve any emails. SOmething similar had happened before, but when I shut down again it went away. This time it did not. I then tried to access my emails thru the webmail I can access, but that also had shut me out. I also tried my tablet, a borrowed smart phone, but I could not access anything for my emails. I troubleshooted with my email company and my internet company, but they found nothing.

Then I shut off the wi-fi on the smart phone and bin go I could access the webmail. But I still cannot find anything on what to do to fix this.

I use RCN for my email, Spectrum for my internet. It is a POP3. Running Thunderbird version 153.5 Oesr (32 bit) Meadow, which says it is up to date. I have norton 360 anti virus & do not use VPN. I disabled my Auto-protect and firewall on the Norton and that did not change anything.

I have sent the error messages to RCN and also troubleshot with Microsoft and had some hints, but nothing has come of that yet. Here are the screen shots of the only 2 things I ould capture. The error message was when I was trying to access my email thru Thunderbird. And it came up every time I tried to send messages, not that does not show up anymore and nothing happens when I try and send anything. The second one was when I was trying to access the RCN webmail and it would not let me in on anything I used. Until I shout off the WI-Fi. Then the smart phone could access my webmail account.

Trying to install Thunderbird (the EN-GB) version on Linux using apt. I have found the package to install using the help and used apt-get install thunderbird-l10n-en-gb This command also pulls as a requisite the base thunderbird (the "en-US"/default version) which may or may not be reasonable? When I go into thunderbird help after the install finishes the "about" still shows "Mozilla Thunderbird Debian Package en-US" I know the difference is only subtle (small spellings etc) but I would like to have some confidence in what I am actually running, Is this a bug or was it just never checked? I have attached the help about image below.

I used lightspeed POS program. We have specialized forms that print out for us created by a third-party developer working with light speed. A few months back you updated Firefox and it changed our printing where the forms do not print exactly like before. Can this be fixed by you?

A lot of the "submit" buttons are no longer highlighted, and other buttons too. The blue is no longer a nice rich deep blue. Hyper text is not a clear as it used to be. Sites that were visited previously aren't the same color. I just want to go back to the original classic Firefox look that I've for years. I'm having the same issue with my computer at home. Something happened during the last Firefox update