It may be too early to update to firefox 126.0 as it's not possible to connect to facebook.com.
Not a big deal for me but is for my wife!
This is a clean install and a new profile.
Error: Your tab crashed.

I think they will fix it very soon. I get the same error on X so I guess Mozilla is now full of bug reports

Firefox 126.0-1 is working OK in Archlinux & Endeavouros OS both with Plasma.

What kernel are you running? linux-next > 6.9? (not up in many distros yet), if so, please also try with linux (6.8).

    Hello 🙂

    The tab crashing is happening across multiple social media sites. One commonality in error logs pertaining to these sites is zstd. Take note of What's new in FireFox 126, it mentions -

    Firefox now supports Content-encoding: zstd (zstandard compression). This is an alternative to broti and gzip compression for web content, and can provide higher compression levels for the same CPU used, or conversely lower server CPU use to get the same compression. This is heavily used on sites such as Facebook.

    Here are the error logs, I got while trying to access VKontakte (website loads in full; tab crashes almost instantly) while in case of Facebook & Instagram (website never loads; tab crashes instantly) -

    StreamTrans something -

    15/05/24 11:08 AM kernel StreamTrans #1[46541]: segfault at fd2fb520 ip 00007f9195e00047 sp 00007f918f3ae568 error 6 in libxul.so[7f9195e00000+50000] likely on CPU 7 (core 7, socket 0)
    15/05/24 11:08 AM systemd-coredump Process 46495 (Isolated Web Co) of user 1000 dumped core.
    Stack trace of thread 46541:
    #0 0x00007f9195e00047 n/a (libxul.so + 0x47)
    ELF object binary architecture: AMD x86-64
    15/05/24 11:08 AM systemd systemd-coredump@18-46681-0.service: Deactivated successfully.
    15/05/24 11:08 AM plasmashell [Parent 46305, IPC I/O Parent] WARNING: process 46495 exited on signal 11: file /buildsys/apps/firefox/src/firefox-126.0/ipc/chromium/src/base/process_util_posix.cc:335
    15/05/24 11:08 AM drkonqi-coredump-processor "/usr/lib/firefox/firefox" 46495 "/var/lib/systemd/coredump/core. Isolated\\x20Web\\x20Co.1000.a128902a1ac540878624e34c00c47936.46495.1715751506000000.zst"
    15/05/24 11:08 AM systemd Started Launch DrKonqi for a systemd-coredump crash (PID 46683/UID 0).
    15/05/24 11:08 AM systemd drkonqi-coredump-processor@18-46681-0.service: Deactivated successfully.
    15/05/24 11:08 AM drkonqi-coredump-launcher Unable to find file for pid 46495 expected at "kcrash-metadata/firefox.a128902a1ac540878624e34c00c47936.46495.ini"
    15/05/24 11:08 AM drkonqi-coredump-launcher Nothing handled the dump 😮

    HTML5 something -

    15/05/24 5:52 PM kernel HTML5 Parser[17907]: segfault at 0 ip 00007f330e000060 sp 00007f330dc78788 error 6 likely on CPU 9 (core 1, socket 0)
    15/05/24 5:52 PM kernel Code: 38 00 0a 00 40 00 20 00 1f 00 06 00 00 00 04 00 00 00 40 00 00 00 00 00 00 00 40 00 00 00 00 00 00 00 40 00 00 00 00 00 00 00 <30> 02 00 00 00 00 00 00 30 02 00 00 00 00 00 00 08 00 00 00 00 00
    15/05/24 5:52 PM systemd Started Process Core Dump (PID 18175/UID 0).
    15/05/24 5:52 PM systemd Started Pass systemd-coredump journal entries to relevant user for potential DrKonqi handling.
    15/05/24 5:52 PM systemd-coredump Process 17901 (Isolated Web Co) of user 1000 dumped core.
    Stack trace of thread 17907:
    #0 0x00007f330e000060 n/a (libxul.so + 0x60)
    ELF object binary architecture: AMD x86-64
    15/05/24 5:52 PM systemd systemd-coredump@4-18175-0.service: Deactivated successfully.
    15/05/24 5:52 PM plasmashell [Parent 17405, IPC I/O Parent] WARNING: process 17901 exited on signal 11: file /buildsys/apps/firefox/src/firefox-126.0/ipc/chromium/src/base/process_util_posix.cc:335
    15/05/24 5:52 PM drkonqi-coredump-processor "/usr/lib/firefox/firefox" 17901 "/var/lib/systemd/coredump/core. Isolated\\x20Web\\x20Co.1000.c07ee46b4b234748bc3396bc879ea80c.17901.1715775738000000.zst"
    15/05/24 5:52 PM systemd Started Launch DrKonqi for a systemd-coredump crash (PID 18177/UID 0).
    15/05/24 5:52 PM systemd drkonqi-coredump-processor@4-18175-0.service: Deactivated successfully.
    15/05/24 5:52 PM drkonqi-coredump-launcher Unable to find file for pid 17901 expected at "kcrash-metadata/firefox.c07ee46b4b234748bc3396bc879ea80c.17901.ini"
    15/05/24 5:52 PM drkonqi-coredump-launcher Nothing handled the dump 😮

    Background Pool something -

    15/05/24 5:52 PM kernel Backgro~Pool #2[18239]: segfault at fd2fb520 ip 00007fe8c9200047 sp 00007fe8c25fa568 error 6 in libxul.so[7fe8c9200000+50000] likely on CPU 12 (core 4, socket 0)
    15/05/24 5:52 PM kernel Code: 00 00 00 40 00 00 00 00 00 00 00 08 01 80 08 00 00 00 00 00 00 00 00 40 00 38 00 0a 00 40 00 20 00 1f 00 06 00 00 00 04 00 00 <00> 40 00 00 00 00 00 00 00 40 00 00 00 00 00 00 00 40 00 00 00 00
    15/05/24 5:52 PM systemd Started Process Core Dump (PID 18240/UID 0).
    15/05/24 5:52 PM systemd Started Pass systemd-coredump journal entries to relevant user for potential DrKonqi handling.
    15/05/24 5:52 PM systemd-coredump Process 17992 (Isolated Web Co) of user 1000 dumped core.
    Stack trace of thread 18239:
    #0 0x00007fe8c9200047 n/a (libxul.so + 0x47)
    ELF object binary architecture: AMD x86-64
    15/05/24 5:52 PM systemd systemd-coredump@5-18240-0.service: Deactivated successfully.
    15/05/24 5:52 PM plasmashell [Parent 17405, IPC I/O Parent] WARNING: process 17992 exited on signal 11: file /buildsys/apps/firefox/src/firefox-126.0/ipc/chromium/src/base/process_util_posix.cc:335
    15/05/24 5:52 PM rtkit-daemon Supervising 5 threads of 3 processes of 1 users.
    15/05/24 5:52 PM rtkit-daemon Supervising 5 threads of 3 processes of 1 users.
    15/05/24 5:52 PM drkonqi-coredump-processor "/usr/lib/firefox/firefox" 17992 "/var/lib/systemd/coredump/core. Isolated\\x20Web\\x20Co.1000.c07ee46b4b234748bc3396bc879ea80c.17992.1715775767000000.zst"
    15/05/24 5:52 PM systemd Started Launch DrKonqi for a systemd-coredump crash (PID 18242/UID 0).
    15/05/24 5:52 PM systemd drkonqi-coredump-processor@5-18240-0.service: Deactivated successfully.
    15/05/24 5:52 PM drkonqi-coredump-launcher Unable to find file for pid 17992 expected at "kcrash-metadata/firefox.c07ee46b4b234748bc3396bc879ea80c.17992.ini"
    15/05/24 5:52 PM drkonqi-coredump-launcher Nothing handled the dump 😮

    The tab crashing and corresponding error logs are pretty consistent. Happens everytime, the social media sites are accessed. The problem persists even in Troubleshoot Mode of FireFox, the one where extensions, themes, and custom settings are temporarily disabled.

    The aforementioned sites are perfectly usable on Palemoon, SeaMonkey, Yandex, Falkon, Otter and Vivaldi.

    • demm replied to this.

      Same as Aleid,
      Same with both kernels. Linux-next and linux 6.7.9-1
      only error from command line after firefox --safe-mode is:-

      [Parent 3918, IPC I/O Parent] WARNING: process 4350 exited on signal 11: file /buildsys/apps/firefox/src/firefox-126.0/ipc/chromium/src/base/process_util_posix.cc:335

        Aleid ipc/chromium/src/base/process_util_posix.cc:335

        is the only indication so far, but that one is meaningless, that file only lists that firefox had a tab crash, no reasons at all given as to why, I can't get any more debug either.

            demm Thanks for providing the impetus 🙂

            Added [build] repo and installed kernel 6.9 as well as firmware 20240513, but to no avail. So, I tried the current beta version of FireFox that is 127 and the issue went poof.

              demm Strolled through the changelogs of all recent versions (mainline, beta, nightly, esr) and noticed this in Firefox 126 for developers -

              HTTP
              The zstd directive of the Content-Encoding HTTP header is now supported, allowing decoding of server-sent content encoded with the Zstandard compression algorithm (Firefox bug 1871963).

              Which in turn led to a bunch of regressions regarding the implementation of zstd; stuff that was labelled as broken for version 126 but was fixed in 127. It seems that removal of a certain compilation flag fixes it.

              Seems to attest that this fiasco of firefox was indeed about zstd. As mentioned here -

              brotli achieves compression density by more computation whereas zstd is relying on more memory access (larger window size). Even in the area of normal operation ... zstd, the server has no way to actually know if the client will be able to decode the stream if the request is for more than 8 MB ... zstd defaults to larger window sizes (often 128 MB vs. brotli's 4 MB). When used in a browser environment, usual deployments use smaller window size because larger window sizes mean more OutofMemory errors in browsers.

              And the error logs mentioned in this thread by us, too, categorically point towards Signal 11 (SIGSEGV, segmentation violation) that is the browser tried to accessed a memory location that was not assigned to it.

                Yes, I know there were some sigsev errors listed, that is why I asked about kernel used, but kernel is not it, checked already a few days ago with both 6.8 & 6.9.

                8 days later

                Hello, when opening facebook Firefox console returns

                AbortError: Actor 'ExtensionContent' destroyed before query 'Execute' was resolved ExtensionCommon.sys.mjs:852
    normalizeError resource://gre/modules/ExtensionCommon.sys.mjs:852
    recvAPICall resource://gre/modules/ExtensionParent.sys.mjs:1173
    updateBrowserRemoteness chrome://browser/content/tabbrowser.js:1919
    sendToTabCrashedPage resource:///modules/ContentCrashHandlers.sys.mjs:543
    flushCrashedBrowserQueue resource:///modules/ContentCrashHandlers.sys.mjs:215
    observe resource:///modules/ContentCrashHandlers.sys.mjs:134

                When loading X returns (first part of the message is automatically translated so it may not be accurate):

                Content-Security-Policy: Page settings blocked the execution of an inline script (script-src-elem) as it infringes the following directive: “script-src 'self' 'unsafe-inline' https://*.twimg.com https://recaptcha.net/recaptcha/ https://www.google.com/recaptcha/ https://www.gstatic.com/recaptcha/ https://client-api.arkoselabs.com/ https://www.google-analytics.com https://twitter.com https://x.com https://accounts.google.com/gsi/client https://appleid.cdn-apple.com/appleauth/static/jsapi/appleid/1/en_US/appleid.auth.js https://www.gstatic.com/cast/sdk/libs/caf_receiver/v3/cast_receiver_framework.js https://static.ads-twitter.com 'nonce-MGZmNmJlN2ItYjgyNy00ZGRjLTgxZWQtMTA2ZDU1MjJlMDc4'” 2 content.js:60:437
                I don't know if it helps. I hope yes

                4 days later
                4 days later

                Just a little observation, since this bug doesn't happen on other installs I have with Debian and Manjaro, it must be something up with zstd because if you go to "about:config" in Firefox and look for "network.http.accept-encoding.secure" and delete "zstd" in the preference line there, the pages that were blocked suddenly work, but I only have to delete that on KaOS, no need to do it on other OS