<application>
        <resource-bundle>
            <base-name>nls.messages</base-name>
            <var>msg</var>
        </resource-bundle>
    </application>

<h:body>
        #{msg.app_name}
    </h:body>

TAL:   JSF1073: javax.el.ELException caught during processing of RENDER_RESPONSE 6 : UIComponent-ClientId=, Message=/index.xhtml: Can't find bundle for base name nls.messages, locale ru_RU
FATAL:   /index.xhtml: Can't find bundle for base name nls.messages, locale ru_RU
javax.el.ELException: /index.xhtml: Can't find bundle for base name nls.messages, locale ru_RU