I seem to have the same apparmor problem with Chrome under Lubuntu 24.04. From "$ journalctl | grep apparmor | grep chrome" I got info="Userns create restricted - failed to find unprivileged_userns profile" (among other things). And it's been reproduced by another as the following relates.

EDIT: This is all in a live boot environment.

Can anyone help? Much more detail below. And you can email me: <email address hidden>.

Prior Lubuntu versions, I wget'd the latest Chrome deb from Google and installed it via sudo dpkg -i. Usually it worked quite well. Now with Lubuntu 24.04, I downloaded the latest Chrome deb the same way on Apr. 28, 2024, but Chrome's not working.

If I run /usr/bin/google-chrome or /usr/bin/google-chrome-stable:

```
$ google-chrome
[55151:55151:0428/224255.271437:FATAL:credentials.cc(127)] Check failed: . : Permission denied (13)
Trace/breakpoint trap (core dumped)
```

or

```
$ google-chrome-stable
[55166:55166:0428/224300.689874:FATAL:credentials.cc(127)] Check failed: . : Permission denied (13)
Trace/breakpoint trap (core dumped)
```

Meanwhile, $ sudo netstat -antvp shows active connections to multiple IPs associated with Google, presumably because I tried multiple times to get Chrome to launch.

Then,

```
$ ls /etc/apparmor.d
1password           firefox         lxc-stop         rootlesskit           scide                  usr.bin.redshift
Discord             flatpak         lxc-unshare      rpm                   signal-desktop         usr.bin.tcpdump
MongoDB_Compass     force-complain  lxc-usernsexec   rssguard              slack                  usr.lib.libreoffice.program.oosplash
QtWebEngineProcess  geary           mmdebstrap       rsyslog.d             slirp4netns            usr.lib.libreoffice.program.senddoc
abi                 github-desktop  msedge           runc                  steam                  usr.lib.libreoffice.program.soffice.bin
abstractions        goldendict      nautilus         sbuild                stress-ng              usr.lib.libreoffice.program.xpdfimport
brave               ipa_verify      notepadqq        sbuild-abort          surfshark              usr.lib.snapd.snap-confine.real
buildah             kchmviewer      nvidia_modprobe  sbuild-adduser        systemd-coredump       usr.sbin.cups-browsed
busybox             keybase         obsidian         sbuild-apt            thunderbird            usr.sbin.cupsd
cam                 lc-compliance   opam             sbuild-checkpackages  toybox                 usr.sbin.rsyslogd
ch-checkns          libcamerify     opera            sbuild-clean          trinity                uwsgi-core
ch-run              linux-sandbox   pageedit         sbuild-createchroot   tunables               vdens
chrome              local           plasmashell      sbuild-destroychroot  tup                    virtiofsd
code                loupe           podman           sbuild-distupgrade    tuxedo-control-center  vivaldi-bin
crun                lsb_release     polypane         sbuild-hold           ubuntu_pro_apt_news    vpnns
devhelp             lxc-attach      privacybrowser   sbuild-shell          unix-chkpwd            wpcom
element-desktop     lxc-create      qcam             sbuild-unhold         unprivileged_userns
epiphany            lxc-destroy     qmapshack        sbuild-update         userbindmount
evolution           lxc-execute     qutebrowser      sbuild-upgrade        usr.bin.man
```

and 

```
$ cat /etc/apparmor.d/chrome
# This profile allows everything and only exists to give the
# application a name instead of having the label "unconfined"

abi <abi/4.0>,
include <tunables/global>

profile chrome /opt/google/chrome/chrome flags=(unconfined) {
  userns,

  # Site-specific additions and overrides. See local/README for details.
  include if exists <local/chrome>
}
```

This didn't work either:

```
$ /opt/google/chrome/chrome
[0429/105700.793962:WARNING:chrome_main_linux.cc(80)] Read channel stable from /opt/google/chrome/CHROME_VERSION_EXTRA
[66808:66808:0429/105700.802212:FATAL:credentials.cc(127)] Check failed: . : Permission denied (13)
Trace/breakpoint trap (core dumped)
```

Note that I also ran this:

```
$ journalctl | grep apparmor | grep chrome
Apr 28 21:22:42 lubuntu kernel: audit: type=1400 audit(1714364562.824:140): apparmor="STATUS" operation="profile_replace" profile="unconfined" name="snap.chromium.chromedriver" pid=19182 comm="apparmor_parser"
Apr 28 22:04:11 lubuntu kernel: audit: type=1400 audit(1714367051.521:200): apparmor="DENIED" operation="userns_create" class="namespace" info="Userns create restricted - failed to find unprivileged_userns profile" error=-13 profile="unconfined" pid=46114 comm="chrome" requested="userns_create" denied="userns_create" target="unprivileged_userns"
```

Someone else reproduced this, following these steps:
```
    1. figured out what version of apparmor contained the fix
    2. booted the live image
    3. checked that the version of apparmor on the live image was greater than or equal to the version with the fix
    4. installed chrome
    5. ran chrome on the command line, specifically using the path specified in the apparmor profile
    6. got the same error you did
    7. checked the logs and i see the error that it can't find the profile
```

Can anyone help? Maybe there's a way for me to pull off the unconfined apparmor workaround?