Fatal Error? In Featured Content

So, I finally removed the Featured Content plugin in my website and got posts working. Now, this shows up:

Fatal error: Call to undefined function get_a_post() in D:\Hosting\4569680\html\wp-content\plugins\featured-content-gallery\gallery.php on line 31

How do I fix this?

Here is my Index.php:
https://wordpress.pastebin.ca/1657053