HTTP Status 500 - info.magnolia.module.admininterface.InvalidTreeHandlerException: Unable to instantiate a tree handler for [Contact] due to a info.magnolia.content2bean.Content2BeanException exception

type Exception report

message info.magnolia.module.admininterface.InvalidTreeHandlerException: Unable to instantiate a tree handler for [Contact] due to a info.magnolia.content2bean.Content2BeanException exception

description The server encountered an internal error that prevented it from fulfilling this request.

exception

java.lang.RuntimeException: info.magnolia.module.admininterface.InvalidTreeHandlerException: Unable to instantiate a tree handler for [Contact] due to a info.magnolia.content2bean.Content2BeanException exception
	info.magnolia.module.cache.filter.CacheFilter.doFilter(CacheFilter.java:165)
	info.magnolia.cms.filters.OncePerRequestAbstractMgnlFilter.doFilter(OncePerRequestAbstractMgnlFilter.java:61)
	info.magnolia.cms.filters.MgnlFilterChain.doFilter(MgnlFilterChain.java:83)
	info.magnolia.cms.i18n.I18nContentSupportFilter.doFilter(I18nContentSupportFilter.java:76)
	info.magnolia.cms.filters.AbstractMgnlFilter.doFilter(AbstractMgnlFilter.java:91)
	info.magnolia.cms.filters.MgnlFilterChain.doFilter(MgnlFilterChain.java:83)
	info.magnolia.cms.filters.RangeSupportFilter.doFilter(RangeSupportFilter.java:84)
	info.magnolia.cms.filters.AbstractMgnlFilter.doFilter(AbstractMgnlFilter.java:91)
	info.magnolia.cms.filters.MgnlFilterChain.doFilter(MgnlFilterChain.java:83)
	info.magnolia.cms.security.BaseSecurityFilter.doFilter(BaseSecurityFilter.java:60)
	info.magnolia.cms.filters.AbstractMgnlFilter.doFilter(AbstractMgnlFilter.java:91)
	info.magnolia.cms.filters.MgnlFilterChain.doFilter(MgnlFilterChain.java:83)