The stable evolution-3.42.4 and webkit-gtk-2.36.x are incompatible for me: https://bugs.webkit.org/show_bug.cgi?id=238721 It looks like evolution-3.44.1 has a workaround for it, "Disable hardware acceleration for WebKitGTK": https://mirror.csclub.uwaterloo.ca/gnome/sources/evolution/3.44/evolution-3.44.1.news In any case, updating evolution fixes the problem reported in that webkit bug, but requires you to keyword unstable evolution stuff alongside the stable webkit-gtk.
It's pending in bug 843794. But maybe we should backport something to evo-3.42.x?
New evolution is stabilized.