NFe XML Parser for Object

I'm trying to make an XML parser from NFe for the TNFeProc object, and I always get the error:

java.lang.IllegalArgumentException: can't parse argument number: {0}
at java.text.MessageFormat.makeFormat(MessageFormat.java:1429)
at java.text.MessageFormat.applyPattern(MessageFormat.java:479)
at java.text.MessageFormat.<init>(MessageFormat.java:362)
at java.text.MessageFormat.format(MessageFormat.java:840)
at com.sun.xml.internal.bind.v2.model.impl.Messages.format(Messages.java:117)
at com.sun.xml.internal.bind.v2.model.impl.ReferencePropertyInfoImpl.calcTypes(ReferencePropertyInfoImpl.java:171)
at com.sun.xml.internal.bind.v2.model.impl.ReferencePropertyInfoImpl.link(ReferencePropertyInfoImpl.java:372)
at com.sun.xml.internal.bind.v2.model.impl.ClassInfoImpl.link(ClassInfoImpl.java:1257)
at com.sun.xml.internal.bind.v2.model.impl.RuntimeClassInfoImpl.link(RuntimeClassInfoImpl.java:182)
at com.sun.xml.internal.bind.v2.model.impl.ModelBuilder.link(ModelBuilder.java:439)
at com.sun.xml.internal.bind.v2.model.impl.RuntimeModelBuilder.link(RuntimeModelBuilder.java:118)
at com.sun.xml.internal.bind.v2.runtime.JAXBContextImpl.getTypeInfoSet(JAXBContextImpl.java:443)
at com.sun.xml.internal.bind.v2.runtime.JAXBContextImpl.<init>(JAXBContextImpl.java:277)
at com.sun.xml.internal.bind.v2.runtime.JAXBContextImpl.<init>(JAXBContextImpl.java:124)
at com.sun.xml.internal.bind.v2.runtime.JAXBContextImpl$JAXBContextBuilder.build(JAXBContextImpl.java:1123)
at com.sun.xml.internal.bind.v2.ContextFactory.createContext(ContextFactory.java:147)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at javax.xml.bind.ContextFinder.newInstance(ContextFinder.java:247)
at javax.xml.bind.ContextFinder.newInstance(ContextFinder.java:234)
at javax.xml.bind.ContextFinder.find(ContextFinder.java:462)
at javax.xml.bind.JAXBContext.newInstance(JAXBContext.java:641)
at javax.xml.bind.JAXBContext.newInstance(JAXBContext.java:584)
at br.indie.parser.app.Execute.getNFe(Execute.java:32)
at br.indie.parser.app.Execute.main(Execute.java:22)

Caused by: java.lang.NumberFormatException: For input string: "{0}"

Method responsible for the parser:

public static TNfeProc getNFe(String xml) throws Exception {
    try {
        JAXBContext context = JAXBContext.newInstance(TNfeProc.class);
        Unmarshaller unmarshaller = context.createUnmarshaller();
        TNfeProc nfe = unmarshaller.unmarshal(new StreamSource(new StringReader(xml)), TNfeProc.class).getValue();
        return nfe;
    } catch (JAXBException ex) {
        throw new Exception(ex.toString());
    }
}