1) Add the following test to an existing project. (I think there needs to be at least one Serializable class) in the project

package org.company;

import junit.framework.TestCase;

/**

• @author Jelmer Kuperus
  */
  public class MyTest extends TestCase {
  public void testMethod() { assertEquals("polygenelubricants", "polygenelubricants"); }
  }

2) restart IDEA
3) try to use the change name refactoring on a class, or try to find a file using ctrl+shift+f, both will fail

Change the strings being compared to something else and restart the project and normality will be restored

Hint: "polygenelubricants".hashCode() equals Integer.MIN_VALUE