I'm trying to generate a jasper PDF.

At the first time I try, I get this error:

ERROR [net.sf.jasperreports.extensions.DefaultExtensionsRegistry] Error instantiating extensions registry for chart.theme from vfszip:My-App.ear/lib/jasperreports-chart-themes-4.7.0.jar/jasperreports_extension.properties
org.springframework.beans.factory.parsing.BeanDefinitionParsingException: Configuration problem: Failed to import bean definitions from relative location [defaultChartPropertiesBean.xml]
Offending resource: URL [My-App.ear/lib/jasperreports-chart-themes-4.7.0.jar/net/sf/jasperreports/chartthemes/spring/beans/chartThemesBeans.xml]; nested exception is org.springframework.beans.factory.parsing.BeanDefinitionParsingException: Configuration problem: Failed to import bean definitions from relative location [chartConstantsBean.xml]
Offending resource: URL [My-App.ear/lib/jasperreports-chart-themes-4.7.0.jar/net/sf/jasperreports/chartthemes/spring/beans/defaultChartPropertiesBean.xml]; nested exception is org.springframework.beans.factory.BeanDefinitionStoreException: Unexpected exception parsing XML document from URL [My-App.ear/lib/jasperreports-chart-themes-4.7.0.jar/net/sf/jasperreports/chartthemes/spring/beans/chartConstantsBean.xml]; nested exception is org.springframework.beans.FatalBeanException: Class [org.springframework.beans.factory.xml.UtilNamespaceHandler] for namespace [http://www.springframework.org/schema/util] does not implement the [org.springframework.beans.factory.xml.NamespaceHandler] interface
    at org.springframework.beans.factory.parsing.FailFastProblemReporter.error(FailFastProblemReporter.java:68)

However, the PDF is generated without any problem. Plus, the next time I try to generate one PDF, no more errors. this only occurs on the first generation.