Safari tab titles missing Mac El Capitan
My safari tab titles were blank I was able to fix this.
Clear your history safari 100%
Quit Safari. or force quit by at apple icon.
Start safari with the shift key pressed.
Close safari.
Restart safari and your tabs should be titled. This worked for me.
I tested this by going to and opening a new user. Any new users didn't have this issue. So I knew settings were the issue.
iMac, OS X El Capitan (10.11.5)