When I try to export a database model it happen the follow errors:

• ClassCastException exporting an unique key:
  java.lang.ClassCastException: org.hibernate.metamodel.relational.Column cannot be cast to org.hibernate.mapping.Column
  at org.hibernate.dialect.unique.DefaultUniqueDelegate.uniqueConstraintSql(DefaultUniqueDelegate.java:137)
• Primary Keys are exported as Unique key
• Sequences are not created
  Caused by: org.h2.jdbc.JdbcSQLException: Sequence "hibernate_sequence" not found; SQL statement:
  call next value for "hibernate_sequence" [90036-145]
  at org.h2.message.DbException.getJdbcSQLException(DbException.java:327)