Problem with Json deserialization of class extension using Jackson - No converter found for return value of type

Question

I have a problem with deserializing json using jackson. I am using spring-boot framework and there I have jackson dependecies, so this is not an issue.

In one project A I have a class User and in project B (which is referencing project A through maven dependency), I have an extension class of the User class, the UserExtension class.

When I test the GET method using Swagger, I get the following exception: "No converter found for return value of type:..."

I tried adding manually getters and setters for the User fields in the UserExtension class, but it didn't work. Do you have any suggestion of what I could change? Is there a way to solve this without writing custom Json Serializors and Deserializors?

@JsonSerialize
@Getter
@Setter
@AllArgsConstructor
@NoArgsConstructor
@EqualsAndHashCode
public class User {
                  private String id;
                  private String name;
}

@JsonSerialize
@Getter
@Setter
@AllArgsConstructor
@NoArgsConstructor
@EqualsAndHashCode
 public class UserExtension {
      private String email;
      private String quote;
              @JsonUnwrapped 
              @NotNull
      private User user;
      public String getId() {
               return user.getId();
      }
      public String getName() {
              return user.getName();
      }
      public void setId(String id) {
              user.setId(id);
      }
      public void setName(String name) {
              user.setName(name);
      }
   }