I have found the issue: the problem was inside the pom.xml of the ear module

<dependencies>
        <dependency>
            <groupId>com.example</groupId>
            <artifactId>APPNAME-ejb</artifactId>
            <version>${project.version}</version>
            <type>ejb</type>
        </dependency>
        <dependency>
            <groupId>com.example</groupId>
            <artifactId>APPNAME-web</artifactId>
            <version>${project.version}</version>
            <type>war</type>
        </dependency>
    </dependencies>

these dependencies after build block in the xml file were not added; after the edit the error disappeared.