title: "Invalid signature file" when attempting to run a .jar
body: <p>My java program is packaged in a jar file and makes use of an external jar library, <a href="http://www.bouncycastle.org/" rel="noreferrer">bouncy castle</a>. My code compiles fine, but running the jar leads to the following error:</p>
  
  <p><strong>Exception in thread "main" java.lang.SecurityException: Invalid signature file digest for Manifest main attributes</strong></p>
  
  <p>I've googled for over an hour searching for an explanation and found very little of value. If anyone has seen this error before and could offer some help, I would be obliged.</p>