Costeef Yépp Community Forum

Hi everyone,

I’ve noticed that Firefox tends to use a lot of memory when I run several browser-based tools at once — especially web calculators or dashboards that update data dynamically.

For example, when I’m testing a lightweight web calculation app (something similar to a gratuity calculator that updates values in real time), Firefox memory usage slowly increases, and sometimes the browser even freezes if multiple tabs are open.

I’ve already tried:

Clearing cache and disabling extensions

Running in Safe Mode

Using hardware acceleration on/off

Still, the problem persists.

So I’d like to ask:

1. Are there any specific settings or flags that can help manage memory usage better for interactive web tools?

2. Does Firefox handle JavaScript-heavy calculations differently compared to Chromium-based browsers?

3. Any recommended performance tweaks for developers testing such tools locally?

Would really appreciate advice from anyone who’s optimized Firefox for this kind of lightweight, web-app testing.

Thanks in advance! 🙏 bold text

Just over a week ago, I found that a particular page transition always crashed by browser tab (i.e. a reproducible crash). This occurred on the Quora.com website when visiting the 'Questions' tab for any Quora Space. I am not aware of anything special associated with this operation, and it works OK in Chrome. There may be other cases -- outside of that particular website -- but that is the one most affecting me at the moment.

There are no associated Windows events logged. I checked about:crashes and the Crash Report folder but i cannot find any readable details.

If I refresh the page then the transition occurs without problem.

I would like to find the cause myself because I am on an Windows 7 64-bit ESR version, although I do not believe this is an ESR issue as it was working fine a couple of weeks ago. it is just that I cannot find any logged information on the cause.

Hi

i use Mozilla at work, in logistics.

When booking shippments we use "nShift". Booking is repetitive, so the autofill function (in swedish its autofyll) is pretty useful, and we have used it extensively...now for some reason it has just disappeared and we cant get back.

See uppploaded imgage, tried to follow the instructions,..... also in my edition there is no subheading caled "Formulär & autofyll", it just says "Autofyll".

So the question is, what to do to get the autofill back.

Thnaks for all the help i can get.

///

My e-mails are sorted from earliest (top) to the latest (bottom). Suddenly about 15 messages have gone out of order. Early ones have appeared towards the bottom (later ones, have appeared under those). Is there an easy way of moving them so they are all sequential?

Thanks

Good morning. I opened up Firefox this morning and all 4 rows of shortcuts were missing. I have gone into settings and made sure the settings for 4 rows was still the same. I cannot find them anywhere. Please help

Hi, when i wrote an email, and i wont to attach a file from PC, when i select the file with extension .pdf, the file did not shown in preview pane. I try everything i think, but it wont work.

I'm trying to add accounts through the hosting provider Strato, but as soon as I add a new email, it asks for my name and email address, and I can only click "Next." Then it searches and searches, and I can't cancel without forcibly closing Thunderbird. How can I change this? Why can't I do it manually? Antivirus and firewall are already disabled... it doesn't help.

new 143.0.01

Hallo,

(new information at the end)

in an effort to understand why one s/mime signed message I received could not be verified by Thunderbird (140.3.0esr (64-bit) on Ubuntu 24.04.3 LTS) (error 1041, "unknown problems with this digital signature"), but by all other clients I and others could check (including cli tools openssl, cmsutil), I did a few tests using my own certificate (using rsaEncryption, SHA256).

Inital observation: Messages signed with "openssl smime -sign -in msg.txt -to <email> -from <my-email> -subject test -signer mycert.pem -inkey mykey.pem -out signed.eml" and opened in Thunderbird showed error 1041. Any modifiers like -crlfeol, -text, -binary, ... did not make a difference.

Omitting signed attributes (-noattr) however helped. The signature was verified.

Further investigations now showed that the reason for that is a mismatch of the signing time in the signed attributes block with the RFC 5322 date in the header (or a missing date, which is the reason, the openssl smime output is rejected). If there is no match, Thunderbird shows a 1041 error (unknown problems with the signature).

However, I'm wondering whether such a test a reasonable. The standards don’t instruct MUAs to compare signingTime to the RFC 5322 Date. Flagging a mismatch is not required by spec and in my opinion adds little to no security value. The RFC date header can be easily modified and the signing time is openly readable.

Does anyone knows why it has been decided to test that?

Good morning.

Problem 1. I've been using Thunderbird for a very long time. Everything has always been fine. But recently, I've been having trouble sending email from one of my accounts. When I try to send a message, a message appears: enter the password for the user... Entering the password doesn't help, and another message appears asking me to contact the network administrator. I contacted them, but they didn't find the cause of the problem, but they suggested changing the password, which I did, and reinstalling Thunderbird, which I didn't do for fear of losing all my email. Changing the password helped for maybe two weeks, and then the problem started all over again. The problem only affects one email address and only on one computer. Sending messages from that address on Android works without any problems.

Problem 2. I installed Thunderbird on my Android phone and encountered a problem when adding two accounts: the first installed without a problem, but I can't install the second one because every time I try, I get a message that the incoming mail server check failed - unknown error 42.

Problem 3. I'm trying to install the program on my second phone - it downloads 99% from the Google Play Store and that's it.

Is there any way to solve these problems, or should I change my email program? Best regards, Andrzej Witkowski

My Thunderbird calendar refuses to display dates in European format, namely day-month-year. I have read lots of helpful hints on the forums and tried everything, but nothing changes. My system is Ubuntu 25.04 with Cinnamon 6.4.8. Thunderbird version is 140.3.0esr (64-bit). Some of the suggestions refer to settings that are no longer there compared to earlier versions. For example, Settings > General > Language and Fonts has no format options. I have also used the config editor while TB was not running and added ntl.date_time.pattern_override.date_short and ntl.date_time.pattern_override.time_short, without any effect. Dates in the calendar still always appear in the illogical American month-day-year format. This is confusing, to say the least ! Has a solution been found to EASILY select the locale and formats that should be used? At the moment, the settings are under different menus and in different locations, and TB seems to be making it as difficult as possible to get these set - permanently ! - to the user's preference.

Thunderbird being used as IMAP client for Gmail - with no issues, until recently when an existing email recipient, who sits behind the Barracuda Networks system, fails to receive mail from Thunderbird's recent versions because it is rejected and blocked by Barracuda. I have tried using plain text formats and checked that SMTP server accounts are correct all to no avail, a 550 blocked is the result. The Thunderbird ver is 143 64 bit - However mail from an earlier 32 bit version 115.5 was successfully delivered, later 32 bit ver 140 failed to deliver through the Barracuda system.

Email from Google's own Web client gets delivered and mail from the Android mobile phone app likewise arrives. A simpler IMAP client (MailSpring) manages to get mail thru Barracuda so what has Thunderbird done to appear a threat to Barracuda ? BTW Mailspring is sort of 'Ok' - but it just isn't Thunderbird - it was installed only as a test vehicle !

When I do "save as " action for an image in the browser it opens dialogue window to save selected image. Unfortunately it displays files and folders in some random order, rather than my preferred order (sorted alphabetically by name, followed by sorting by type).

I can see no rhyme or reason to the way Firefox lists files and folders in the dialogue window, so every time I am saving an image I have to sort things by name and type before I can find what I want.

This is not permanent so I have to repeat this action every time I save an image.

How do I, please set application preferences? to make this setting permanent?

Hello, I imported Bookmarks when I came to Firefox from a previous browser. The experience was terrible and challenges still linger. Firefox has come a long way, however UX still seems to be a 2nd class citizen. Bookmarks now has somewhat duplicate directories and this in turn is causing desktop/phone sync doubt and is likely missing bookmarks.

When sync breaks, it is so confusing. How can I simply have a working Bookmarks sync on desktop/phone?

Perhaps there was a challenge when I need Bookmarks to appear in the top bar when a new Tab is opened, as this was contrary to default Firefox settings.

when copying/pasting files from windows Explorer using the keyboard shortcut Ctrl+C/Ctrl+V in firefox, only the first file of the copied ones is inserted. there are no problems with other browsers (Google).