Right click toolbar, select Customise.
You should see the buttons in the left pane and can Add them to the right pane (hopefully). OR click the Reset button which will get you back to the defaults.
Hands-on: Acer Predator Triton 700 review
1995-2015: How technology has changed the world in 20 years
D&AD Awards 2017: see the best design, advertising, illustration, animation and VR of the past year
Apple predictions 2017
Synology invites you to visit them at Insomnia on 26th – 29th August. Book your tickets now and visit Synology.