Update to most recent version. Problem with this is, that it requires QT5. To make it work, links to the QT packages are required. See my home, where all required packages are (linking to KDE:Qt51).
Even for Factory QT5.1 is not default yet, but it is more than a half years now, that I could not do updates, so I propose to create the links and add Qt5 to Documentation:Tools. The 5.1 packages should work fine together with 4.0 (unlikely the 5.0 ones previously), so I don't expect conflicts anymore.
OBS-URL: https://build.opensuse.org/request/show/198142
OBS-URL: https://build.opensuse.org/package/show/Documentation:Tools/sigil?expand=0&rev=5