java.lang.LinkageError: loader (instance of org/glassfish/web/loader/WebappClassLoader): attempted duplicate class definition for name: "org/glassfish/web/loader/JdbcLeakPrevention" code example

Example: java.lang.LinkageError: loader (instance of org/glassfish/web/loader/WebappClassLoader): attempted duplicate class definition for name: "org/glassfish/web/loader/JdbcLeakPrevention"

I Had the same error. I stopped the GLassfish server and then I cleaned the project (Project -> Clean... ). Started the server and worked