spring mvc json Internal Server Error - spring-mvc

Question

I have problem with returning JSON from controller with response body, i see that that hibernate make query to database but in moment of converting list to json i get in firebug Internal Server Error 500;
my servlet.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans:beans xmlns="http://www.springframework.org/schema/mvc" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:beans="http://www.springframework.org/schema/beans" xmlns:mvc="http://www.springframework.org/schema/mvc"
xmlns:p="http://www.springframework.org/schema/p" xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
<annotation-driven />
<mvc:annotation-driven />
<mvc:default-servlet-handler />
<mvc:resources mapping="/resources/**" location="/resources/" />
<context:annotation-config />
<context:component-scan base-package="pl.daniluk.spotted.controller" />
<beans:bean id="viewResolver" class="org.springframework.web.servlet.view.UrlBasedViewResolver">
<beans:property name="viewClass">
<beans:value>
org.springframework.web.servlet.view.tiles2.TilesView
</beans:value>
</beans:property>
<beans:property name="contentType" value="text/html; charset=UTF-8"></beans:property>
</beans:bean>
<beans:bean id="tilesConfigurer" class="org.springframework.web.servlet.view.tiles2.TilesConfigurer">
<beans:property name="definitions">
<beans:list>
<beans:value>/WEB-INF/tiles.xml</beans:value>
</beans:list>
</beans:property>
</beans:bean>
and controler with #ResponseBody
#Controller
#RequestMapping("/place")
public class PlaceControler {
#Autowired
private PlaceService placeService;
#RequestMapping(value = "/list", method = RequestMethod.GET)
#ResponseBody
public List<Place> getAllPlaces() {
return placeService.getAllPlaces();
}
}
any clues where i'm making mistake?