I've read this and this questions and tried to do what is supposed there (editing ubuntu-helpers, restarting apparmor) but it seems that in ubuntu 15.04 ubuntu-helpers already contains the lines needed and I still get message "application crashed" (or whatever it looks in English) about Google Chrome when I first click on hyperlink in pdf in Evince (all the next clicks just do nothing).
I'm really frustrated and don't know what else to do.