2 days ago i did a distribution upgrade (after a year or so leaving the system as is) and Evolution stopped working. It showed all my incoming mails, sent, trash... but i couldn't open them. Only a blank screen where the body of the mail should show up. It was not possible to write a new mail, same blank screen.
After a lot of searching i found something in an old post, forgot where. Open a terminal en write: WEBKIT_DISABLE_COMPOSITING_MODE=1 press enter, ét voila, works like a charm.

I really don't know what this cryptic message means, but hey, it works.