1) Copy en.po file form folder /lang of the theme or download from demo site here
2) Download Poedit tool here then runt setup this tool
3) Open en.po by Poedit tool => transate the file => Save => System auto generator a new new file with name: en.mo
4) Copy en.mo file and upload into your server root/wp-content/lang/ folder. The correct path of en.mo file is: root/wp-content/lang/en.mo.
Note: In the first time – you have to create the “lang” folder.