Often time, Tomcat may hits the following java.lang.OutOfMemoryError: PermGen space error. java.lang.OutOfMemoryError: PermGen space at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClass(ClassLoader.java:620) at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:124) It’s usually happened after the Tomcat restarts a few times. 1. Solution By defa