GNOME multiwriter starts as expected, but crashes when a USB drive is inserted, with the following error: gnome-multi-writer: symbol lookup error: gnome-multi-writer: undefined symbol: g_usb_context_find_by_bus_address THis error is also returned if multiwriter is started with the drive already inserted. Was testing this update: https://admin.fedoraproject.org/updates/gnome-multi-writer-3.15.2-1.fc21
Updating libgusb from libgusb-0.1.6-5.fc21.x86_64 to libgusb-0.2.3-1.fc21.x86_64 fixes this issue for me
gnome-multi-writer-3.15.2-2.fc21,libgusb-0.2.4-1.fc21 has been submitted as an update for Fedora 21. https://admin.fedoraproject.org/updates/gnome-multi-writer-3.15.2-2.fc21,libgusb-0.2.4-1.fc21
Package gnome-multi-writer-3.15.2-2.fc21, libgusb-0.2.4-1.fc21: * should fix your issue, * was pushed to the Fedora 21 testing repository, * should be available at your local mirror within two days. Update it with: # su -c 'yum update --enablerepo=updates-testing gnome-multi-writer-3.15.2-2.fc21 libgusb-0.2.4-1.fc21' as soon as you are able to. Please go to the following url: https://admin.fedoraproject.org/updates/FEDORA-2015-0483/gnome-multi-writer-3.15.2-2.fc21,libgusb-0.2.4-1.fc21 then log in and leave karma (feedback).
gnome-multi-writer-3.15.2-2.fc21, libgusb-0.2.4-1.fc21 has been pushed to the Fedora 21 stable repository. If problems still persist, please make note of it in this bug report.