internal java compiler error | just learning how to program

I just started to learn how to program about a month ago (forgive me). Still learning how to download things from GitHub & set projects up correctly. 

I downloaded this GitHub library. I'm trying to run the GetCampaigns.java file.

When I try to run it, I get an error that says "java: Compilation failed: internal java compiler error"

Is this because I set the project up incorrectly?