java persistence collection of metamodel types is empty - eclipselink

Question

While deploying my jpa project to wildfly server i am gettings following warning:
The collection of metamodel types is empty.
Model classes may not have been found during entity
search for Java SE and some Java EE container managed persistence units.
Please verify that your entity classes are referenced in persistence.xml using
either <class> elements or a global <exclude-unlisted-classes>false</exclude-unlisted-classes> element
My persistence xml looks like this
<?xml version="1.0" encoding="UTF-8"?>
<persistence xmlns="http://xmlns.jcp.org/xml/ns/persistence" version="2.1">
<persistence-unit name="primary" transaction-type="JTA">
<provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
<jta-data-source>java:jboss/datasources/example</jta-data-source>
<exclude-unlisted-classes>false</exclude-unlisted-classes>
<properties>
<property name="javax.persistence.schema-generation.database.action" value="drop-and-create"/>
<property name="javax.persistence.schema-generation.create-source" value="metadata"/>
<property name="javax.persistence.schema-generation.drop-source" value="metadata"/>
<property name="eclipselink.target-server" value="JBoss"/>
<property name="eclipselink.weaving" value="static"/>
<property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver"/>
<property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost/example"/>
<property name="javax.persistence.jdbc.user" value="root"/>
<property name="javax.persistence.jdbc.password" value="xxx"/>
</properties>
</persistence-unit>
</persistence>
My Database tables are not created due to this.
Please help me understand this problem. As i am not able to understand the root cause of this.

Answer 1

For people who would come across this question like I did: I've just met this issue in Eclipse 2020-06 when running JPA Tools > Generate Tables from Entities, which is a situation probably different from the one in the question albeit with a strictly identical error message.
It turns out that the only thing needed to work around it is to hit Project > Clean and select the JPA project in the list.
For some unknown reason in my case, cleaning the project is necessary between runs of the Generate Tables command. I can't figure out why but that's the way it is. HTH