title: Error: Could not find or load main class - Whenever I make a new Java file
body: <p>I'm currently working on a group project. We are using Eclipse to make a Java program and using e-git (Eclipse extension) to work together. </p>
  
  <p>For some reason today, whenever I try to make a new Java file in the package, it  shows me the following error:</p>
  
  <blockquote>
    <p>Error: Could not find or load main class projectPackage.filename</p>
  </blockquote>
  
  <p>I have no idea what is causing the error as it was working fine yesterday.</p>