Hibernate/JPA project exception

sometimes i get this exception:

message:
updater is null, use setUpdater(Updater) after construction of GenericJpaProject

stack trace:
java.lang.IllegalStateException: updater is null, use setUpdater(Updater) after construction of GenericJpaProject
at org.eclipse.jpt.core.internal.GenericJpaProject.update(GenericJpaProject.java:691)
at org.eclipse.jpt.core.internal.GenericJpaDataSource$LocalConnectionListener.opened(GenericJpaDataSource.java:172)
at org.eclipse.jpt.db.internal.DTPConnectionProfileWrapper$LocalConnectionListener.opened(DTPConnectionProfileWrapper.java:362)
at org.eclipse.datatools.connectivity.internal.ManagedConnection.createConnection(ManagedConnection.java:172)
at org.eclipse.datatools.connectivity.internal.CreateConnectionJob.run(CreateConnectionJob.java:56)
at org.eclipse.core.internal.jobs.Worker.run(Worker.java:55)