carousel arrow icon doesn't show

In home page, the carousel arrow icon of Slide doesn’t show up. Can you please let me know how to fix it? Is that because the arrow icon file doesn’t exist?

I snapped the screenshot about how it looks like if you want to take a look.
https://www.dropbox.com/s/illtfpkscm9rsjo/Screen%20Shot%202016-01-20%20at%2010.47.36%20PM.png?dl=0

Thanks