could you get a backtrace as described on https://wiki.ubuntu.com/DebuggingProgramCrash ?
** Changed in: transmission (Ubuntu) Status: Confirmed => Incomplete -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to transmission in Ubuntu. https://bugs.launchpad.net/bugs/1922884 Title: transmission-gtk segfault (core dumped) Status in transmission package in Ubuntu: Incomplete Bug description: Unable to launch transmission-gtk application, segfault. Ubuntu 21.04 up-to-date. ProblemType: Bug DistroRelease: Ubuntu 21.04 Package: transmission-gtk 3.00-1ubuntu1 ProcVersionSignature: Ubuntu 5.11.0-13.14-generic 5.11.7 Uname: Linux 5.11.0-13-generic x86_64 ApportVersion: 2.20.11-0ubuntu61 Architecture: amd64 CasperMD5CheckResult: unknown CurrentDesktop: ubuntu:GNOME Date: Wed Apr 7 09:47:02 2021 ProcEnviron: TERM=xterm-256color PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=fr_FR.UTF-8 SHELL=/bin/bash SourcePackage: transmission UpgradeStatus: Upgraded to hirsute on 2020-06-09 (301 days ago) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/transmission/+bug/1922884/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp