Invalid action class configuration that references an unknown class named

I have an application in Struts2 and Spring with Maven, but when trying to perform an action, the following error occurs:

Invalid action class configuration that references an unknown class named 

Exception:

java.lang.RuntimeException: Invalid action class configuration that references an unknown class named [ThemeAction]
  org.apache.struts2.convention.ConventionsServiceImpl.determineResultPath(ConventionsServiceImpl.java:99)

This is the configuration of the Struts in pom.xml

<dependency>
    <groupId>org.apache.struts</groupId>
    <artifactId>struts2-core</artifactId>
    <version>${org.strutsframework-version}</version>
</dependency>

<dependency>
    <groupId>org.apache.struts</groupId>
    <artifactId>struts2-spring-plugin</artifactId>   
    <version>${org.strutsframework-version}</version>
</dependency>

<dependency>
    <groupId>org.apache.struts</groupId>
    <artifactId>struts2-convention-plugin</artifactId>
    <version>${org.strutsframework-version}</version>
</dependency>

In this way I call an action of Struts

<action name="actionName" method="execute" class="ClassAction">
    <result name="success">/pages/fileName.jsp</result>    
</action>

and in this way I declare the action in the Spring.xml

<bean class="com.test.action.ClassAction" id="ClassAction">
    <property name="classService" ref="classService"/>
</bean>

How can I solve the error?