Thank you for the quick answer. My OS is ubuntu 16.04 LTS, and currently, I'm using Galaxy by URL on the Firefox (version 51.0.1 (64-bit)). Before asking you about how to solve the issue, I click on the Galaxy icon, as someone suggested on the Biostar forum, but after doing this the problem still persisted in this browser. So, I tried to access Galaxy using the Chromium browser (version 55.0.2883.87), and what I observed was that in this second browser I had no problem, that is, both buttons the refresh and the menu were shown at the top of the History panel. Moreover, after you made the last update, I tried again to access via Firefox browser, and again both the refresh and the cog wheel icons do not appear at the top of the panel, but via Chromium browser, yes they are shown. So, what do you suggest to get the buttons back? Thanks for helping me out with my problem and keep it up. Best!