Java | ServiceException | Unable to create requested Service

This is how my project looks like…

Everytime i try to build a session factory i get following unclear exception…

            Configuration hibernateConfig = new Configuration().configure(hibernateCFGFIle);
            SessionFactory sessionFactory = hibernateConfig.buildSessionFactory();
Exception: org.hibernate.service.spi.ServiceException
Message: Unable to create requested service [org.hibernate.engine.jdbc.env.spi.JdbcEnvironment]
+--- --- ---+
Stack Trace:
+--- --- ---+
org.hibernate.service.internal.AbstractServiceRegistryImpl.createService(AbstractServiceRegistryImpl.java:275)
org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:237)
org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:214)
org.hibernate.id.factory.internal.DefaultIdentifierGeneratorFactory.injectServices(DefaultIdentifierGeneratorFactory.java:152)
org.hibernate.service.internal.AbstractServiceRegistryImpl.injectDependencies(AbstractServiceRegistryImpl.java:286)
org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:243)
org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:214)
org.hibernate.boot.internal.InFlightMetadataCollectorImpl.<init>(InFlightMetadataCollectorImpl.java:176)
org.hibernate.boot.model.process.spi.MetadataBuildingProcess.complete(MetadataBuildingProcess.java:118)
org.hibernate.boot.model.process.spi.MetadataBuildingProcess.build(MetadataBuildingProcess.java:83)
org.hibernate.boot.internal.MetadataBuilderImpl.build(MetadataBuilderImpl.java:473)
org.hibernate.boot.internal.MetadataBuilderImpl.build(MetadataBuilderImpl.java:84)
org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:689)
org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:724)
com.parallelorigin.extension.GameExtension.init(GameExtension.java:132)
com.smartfoxserver.v2.entities.managers.SFSExtensionManager.createExtension(SFSExtensionManager.java:303)
com.smartfoxserver.v2.entities.managers.SFSZoneManager.createRoom(SFSZoneManager.java:719)
com.smartfoxserver.v2.entities.managers.SFSZoneManager.createZone(SFSZoneManager.java:412)
com.smartfoxserver.v2.entities.managers.SFSZoneManager.initializeZones(SFSZoneManager.java:239)
com.smartfoxserver.v2.SmartFoxServer.start(SmartFoxServer.java:292)
com.smartfoxserver.v2.Main.main(Main.java:14)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
java.lang.reflect.Method.invoke(Unknown Source)
com.exe4j.runtime.LauncherEngine.launch(Unknown Source)
com.exe4j.runtime.WinLauncher.main(Unknown Source)
com.install4j.runtime.launcher.WinLauncher.main(Unknown Source)
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

Any idea what causes this exception ? I checked my config file several times… the url, the username, the password… those are all correct.