Visual Editor Missing Buttons Problem

Are you missing all of your visual editor buttons, or just some of them?

All buttons.

Ok, try switching to the Twenty Fifteen theme to rule-out a theme-specific issue (theme functions can interfere like plugins).

I switch theme and still same.

When I click on ‘Visual and Text’ buttons nothing happened.

Ok, try downloading WordPress again and delete then replace your copies of everything except the wp-config.php file and the /wp-content/ directory with fresh copies from the download. This will effectively replace all of your core files without damaging your content and settings. Some uploaders tend to be unreliable when overwriting files, so don’t forget to delete the original files before replacing them.