I think you might have a dodgy browser. I’ve just had it work 5/5 times for each post here, and 2/2 for each post in Cannot edit dashboards
(Opera 48.0 + Ubuntu 16.04 LTS 64-bit)
Similarly Chromium Version 62.0.3202.62 (Official Build) Built on Ubuntu , running on Ubuntu 16.04 (64-bit)