我有一个 JPA 项目，我正在尝试将其更新到 JPA 2.2.0 和 EclipseLink 5.7.1，因为我遇到了EclipseLink 的错误 429992。使用新版本后，我无法再执行我的应用程序 \xe2\x80\x93\xc2\xa0EclipseLink 抛出类似于以下内容的异常（下面示例的简短变体）：
\n\n[EL Warning]: metamodel: 2018-06-20 22:38:14.1--Thread(Thread[main,5,main])--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\n[...]\n\nException in thread "main" java.lang.IllegalArgumentException: Object: Artifact@17d919b6 is not a known Entity type.\n at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.registerNewObjectForPersist(UnitOfWorkImpl.java:4324)\n …