Red Hat Bugzilla – Bug 1315093
[GTK3.20] Firefox scrollbar handles absent in UI scrollbars.
Last modified: 2016-03-22 05:00:26 EDT
After update from gtk3-3.19.10-1 to gtk3-3.19.11-1. The scrollbar handles are absent from UI elements. This especially evident if you do a ctrl-h to display the history sidebar, there is no scrolbar present to scroll the history sidebar.
I vreified that downgrading to gtk3-3.19.10-1 corrected this issue.
Update is here - https://bodhi.fedoraproject.org/updates/FEDORA-2016-44d7ec40fd