This also affected me on Ubuntu 24.04 (Nautilus 46.4, Wayland session). No thumbnails were generated for any file type (PDF, PNG, etc.), even though the individual thumbnailers (evince-thumbnailer, gdk-pixbuf- thumbnailer) worked fine when invoked manually. Using strace, I traced it to bwrap exiting with code 1 due to AppArmor denying "setpcap" and "net_admin" capabilities under the "unprivileged_userns" profile when bwrap tried to create a user namespace (confirmed via dmesg audit logs).
The workaround from comment #5 (creating /etc/apparmor.d/bwrap with a profile granting "userns" to bwrap, then reloading with apparmor_parser -r) fixed it completely for me. Thanks for tracking this down. This bug was fixed by Claude I do not know anything about working with terminal just copy-paste. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2148074 Title: "AppArmor update removes /etc/apparmor.d/nautilus profile, breaking thumbnails in Nautilus (Ubuntu 24.04)" To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/apparmor/+bug/2148074/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
