Hello. According to this post on the devel mailing list, storaged (fork) and udisks have been merged again upstream, so from F26 on, udisks2 is obsoleting storaged; Mediawriter requires need to be changed.
mediawriter-4.1.0-1.fc26 has been submitted as an update to Fedora 26. https://bodhi.fedoraproject.org/updates/FEDORA-2017-729cc5d719
mediawriter-4.1.0-1.fc26 has been pushed to the Fedora 26 stable repository. If problems still persist, please make note of it in this bug report.