Demo menu and pages not working on localhost

Hello I’m working with the theme from a localhost development, that’s the usual way I work when creating websites, but when install the theme and starting uploading the theme dome into my localhost, the pages nor the links on the menu don’t work. Created test pages but and they link to the correct pages (that show on the url) but there no content in it it look like a 404 Not Found page after digging in the code for several hours, I can’t get what the problem is please help with this matter thanks.