Yonke imikhiqizo Community Forum

Hello Mozilla Support Team,

I am experiencing some problems with Firefox. Sometimes the browser becomes slow, pages take a long time to load, and videos do not play smoothly. I have tried refreshing pages and restarting the browser, but the problem still happens.

Could you please help me identify the cause of these issues and explain how I can fix them?

Thank you for your time and support.

Part of my problem has to do with the help aricles that direct me to a format that does not exist on myTbird ap ( 159.0)( on my Macbook pro Tahoe 26.7.1. Another problem is that I am constanly being interrupted by sluggishness occurring in last 3 days, probably from memory demands ot Tbird which is insane, I do not have that many emails and have never seen an email program using memory like this. I need accurate guidance to fix this. Help would be so appreciated.

Thunderbird has bricked on me for the 1st time ever. It won't open my inbox. My cursor turns to the hourglass and there's a dialog that says no message found. It seems to know it's me because I still have tabs across the top where I had open messages and also my name appears in the upper right corner. This is on my Dell Windows 11 desktop. I dont know which version of TB I have but I'm sure I have update set to auto. I just now downloaded version 159 but have not clicked install pending what I can find out here...

Hello!

When I opened Thunderbird today, the main middle pane has an advertisement "Welcome to FREEDOM." How do I get rid of this so that I can see and open my email? I have tried several ideas that I found in the comments before I signed in to this support that asked me to sign in. I tried the suggestions, and none of them work, which is why I came here.

I have attached a screenshot of my entire Thunderbird window. I currently. have 298 emails that I cannot access.

I am currently at work, and really need to be able to access my emails.

Also, I have donated in the past, including earlier this year.

Thank you!

ive just downloaded firefox and its giving me performance issues I play gta 5 all day with my chrome tabs open maybe more then 5 sometimes more then 8 and When I had more then 4 or 5 tabs my gta 5 started to lag when i opened my task manager i see that Firefox is using more then my Game.

Hello,

I was composing a message in TB 159.0 when a shower of duplicate messages appeared. Each message in the central pane was present eight or ten times. In my Tools menu I have an option to Remove Duplicates, I think it's an extension I installed years ago but I can't remember clearly. When I ran it a popup appeared telling me no duplicates could be found, which is ridiculous.

I restored my profile from backup and the problem went away.

I would like to know how I can avoid this issue in the future and, if it happens again, how I can eliminate the duplicates,

Alan.

It's very odd. Normally moving an email, say from the Inbox to the relevant year's archive, takes "no time at all".

Which is true for all the mailboxes shown on the attached screenshot, EXCEPT for the four at the bottom. Moving even one message from Inbox to Yiddish can take ten seconds or longer (with the dreaded "Not Responding" occasionally). Moving something in the opposite direction is also screwy, only from those four.

I had thought that it was because they're rather large. This first started when there were just Yiddish and MSW, and I split off most of the earlier years into the archives shown. To no avail.

It's only an annoyance, but I'm puzzled about how such a thing could happen.

Also very slow tagging or untagging a message just in those mailboxes.

Moderator Notes:

• need a performance profile https://support.mozilla.org/en-US/kb/profiling-thunderbird-performance

To get Thunderbird to display correctly on the screen, you usually need to restart it once or even several times. Even then, Thunderbird is often not fully displayed, as the word ‘Inbox’ appears in italics beneath the email address, with the ‘Junk’ folder below it. Reinstalling Thunderbird has not resolved the issue.

Recently (last week or 2), whenever I delete an email, the unified inbox shows an empty display, but, if I select the three lines and go to inbox and select it, all the expected emails reappear.

Thunderbird is useless. Every time I restart the computer all my emails and personal folders disappear and gradually start to re-appear hours later. I need a reliable email program that leaves my personal items on my computer.

My question can suffice. Once I installed Thunderbird release over the Thunderbird ESR, I have very slow or no access to messages sent before my account was converted to Graph. Confirm?

I was referred here from Thunderbird Bugzilla report 2081665.

We are experiencing a recurring problem with Thunderbird 153 on several Windows workstations in a business environment.

The important point is that the problem also occurs with completely new Thunderbird profiles created from scratch. It is not limited to migrated or old profiles.

On one workstation this has already happened to three separate Thunderbird profiles.

Typical sequence:

1. Thunderbird 153 is installed. 2. A completely new profile is created. 3. Mail accounts are configured manually. 4. Everything initially works normally. 5. After some time the profile begins to malfunction. 6. Thunderbird Settings no longer open/respond. 7. The address books still exist, but address autocomplete when composing a new message stops working. 8. Creating another new profile temporarily fixes the problem, but the same behavior can return later.

Troubleshooting already performed:

- Troubleshoot Mode - extensions disabled - tested without the existing prefs.js - rebuilt Thunderbird caches and profile UI state - recreated indexes/databases - completely removed Thunderbird from Program Files, AppData\Roaming and AppData\Local - clean Thunderbird installation - clean profile created from scratch - Thunderbird executable and profile paths added to Kaspersky Endpoint Security trusted applications/exclusions

Removing prefs.js from an already affected profile did not restore the Settings window.

A clean test profile initially works correctly.

We have also encountered this behavior on other workstations. Some users have more than 100 message filters and many folders, so rebuilding profiles repeatedly causes significant administrative work.

Several affected computers had Windows user accounts renamed in the past.

We also experienced a separate issue where the Attach File dialog stopped appearing while drag-and-drop still worked. Bugzilla identified this as the already known Bug 2077590, so I consider that a separate issue.

For comparison, after completely cleaning Thunderbird from an affected workstation and installing Thunderbird 115.3.1 with a clean profile, the same workstation currently works normally.

Because freshly created Thunderbird 153 profiles can later develop the same problem again, simply recreating the profile does not appear to be a permanent solution.

Environment:

- Windows workstations - Thunderbird 153 ESR - Kaspersky Endpoint Security - multiple IMAP accounts - business environment

What diagnostic information should I collect from the next affected profile before replacing it?

I can provide:

- Thunderbird Troubleshooting Information - Error Console output - profile file names/sizes/timestamps - Windows Event Viewer logs - sanitized prefs.js - comparison with a working fresh profile

Bugzilla report: 2081665 Known separate attachment bug: 2077590

I've noticed that Firefox can sometimes consume a significant amount of RAM when I have multiple tabs open, especially when browsing websites with images, videos, and other media.

I would like to understand:

• Does Firefox handle memory differently compared to other browsers?
• Which built-in Firefox settings can help reduce memory usage?
• Does enabling or disabling hardware acceleration make a difference?

Is there a recommended way to identify which tabs or extensions are consuming the most memory?

I'd appreciate any practical tips or recommended settings to improve Firefox's performance without affecting the browsing experience.

Last update seems to have broken something. The app constantly seizes, freezes, acts like it's crashed, takes over the device OS such that back and minimize buttons don't work, tab access button non-functional, so I can't even close the page that's stuck

In thunderbird when I select Help/Troubleshooting information and than click Open Directory at Profile Directory nothing happens.

Operating System: Fedora Linux 44 KDE Plasma Version: 6.8.2 KDE Frameworks Version: 6.31.0 Qt Version: 6.11.2 Kernel Version: 7.2.13-200.fc44.x86_64 (64-bit) Graphics Platform: Wayland Processors: 8 × Intel® Core™ i7-7700K CPU @ 4.20GHz Memory: 16 GiB of RAM (15.5 GiB usable) Graphics Processor: Quadro RTX 4000

The GPU isn't working properly... I've attached screenshots of the browser I have installed. If needed, I can take any logs, etc. It's very frustrating - I have a fairly old processor and its GPU isn't working properly! If needed, I can create a thread on the forum and attach any information about my system. Sorry if I'm in the wrong place! Best regards, and thank you for the best browser in the world!

When the programme loads the incoming emails are not visible and I can't see the inbox title. I keep pressing the small cloud for incoming messages and eventually the the incoming emails show and I can see the inbox sign.

• • Subject: Severe recurring UI freezes after upgrading Thunderbird from v114 to v150+ — application becomes unresponsive after being left idle**

Hello Thunderbird Support Team,

I'm experiencing a serious and persistent performance issue with Thunderbird that began immediately after upgrading from version 114 to version 150 in September 2026. The problem has continued through multiple subsequent updates and is now severely affecting my daily work.

I've been using Thunderbird for years, and it worked reliably before this major upgrade.

• • The problem**

Thunderbird launches normally and initially works perfectly. However, after I leave it open in the background while working in other applications, it frequently becomes completely unresponsive when I return to it.

Specifically: - Thunderbird is initially fast and responsive after launching. - After approximately 5–10 minutes, or sometimes after a longer period of inactivity, it begins experiencing severe lag or freezes completely. - When I switch back to Thunderbird, the interface is often unresponsive for several minutes. - I often have to force-close the application through Windows because it becomes practically unusable. - Restarting Thunderbird temporarily restores normal performance, but the problem eventually returns, when it's left idle. - The issue occurs repeatedly throughout the day and makes it very difficult to use Thunderbird reliably.

Importantly, this is not simply slow startup performance. Thunderbird initially works perfectly, and the freezing develops after it has been running for a while, particularly when left in the background.

• • Version and environment**

- Operating system: Windows 11 Pro, 64-bit - Thunderbird version before the upgrade: 114 - Version initially upgraded to: 150 - Subsequently confirmed version: 156.0.1 (64-bit), on September 29, 2026 - Problem first appeared: September 2026 - Problem still present: October 22, 2026 - Current Thunderbird version: 158.0.1

• • Troubleshooting already performed**

1. **Global search indexing:** I noticed that Thunderbird's Activity Manager frequently displayed "Indexing messages." I suspected that indexing might be causing the problem.

2. **Disabled Global Search and Indexer (Gloda):** Unfortunately, this made no meaningful difference. Thunderbird continued freezing even with global indexing disabled.

3. **Multiple Thunderbird updates:** The application has been updated repeatedly since the initial upgrade, but the freezing has persisted.

4. **Restarting Thunderbird:** Temporarily resolves the problem, but only until Thunderbird has been running for some time.

• • Additional unusual behavior: Google OAuth authentication**

On at least two occasions, after force-closing an unresponsive Thunderbird process, Google Chrome unexpectedly opened a Google authorization page saying:

"Mozilla Thunderbird Email wants access to your Google Account."

The page also indicated that Thunderbird already had some access to the Google account.

After clicking "Continue," Chrome redirected to a localhost address (127.0.0.1 equivalent, using a dynamically assigned port), which failed with:

"ERR_CONNECTION_REFUSED — localhost refused to connect."

I suspect this happens because Thunderbird is no longer running to receive the OAuth authorization callback.

I'm not sure whether the Google authorization issue is directly related to the freezes, but the repeated timing is suspicious and could indicate a background synchronization or authentication problem.

• • Impact**

I use Thunderbird extensively for professional correspondence and managing my translation business. These recurring freezes are seriously disrupting my workflow.

The problem has now persisted for over a month, despite updates and troubleshooting. It is becoming increasingly difficult to continue using Thunderbird in this condition.

• • What I would appreciate help investigating**

Could you please advise on how to identify the background process or operation that causes Thunderbird to become unresponsive after it has been running for several minutes?

In particular, I would appreciate guidance on:

- Whether this is a known regression affecting users who upgraded from much older Thunderbird versions. - Whether IMAP synchronization, background authentication, or Google OAuth activity could be responsible. - Whether there are diagnostic logs or performance profiles I can collect while Thunderbird is frozen. - Whether a particular database, profile component, or setting could be responsible without requiring me to rebuild my entire Thunderbird setup. - Whether there are known fixes or workarounds.

I'm happy to provide additional diagnostic information, screenshots, or logs if that would help identify the cause.

I would particularly appreciate a way to capture what Thunderbird is actually doing during these freezes, rather than continuing to try speculative troubleshooting steps.

Thank you in advance for your assistance!