I have User entity and I try validate field password for length in my test.
My User Class:
I am surprised that any of the tests would work. Your exception indicates that you have the wrong version of the Unified Expressions Language dependencies on your classpath. See also https://github.com/hibernate/hibernate-validator and http://docs.jboss.org/hibernate/stable/validator/reference/en-US/html_single/#validator-gettingstarted-uel
I guess the question becomes in which environment you are running and which EL dependencies (if any) you are using.