Eclipse Community Forums: Java Development Tools (JDT) » All Java 8 classes opened in 2021-13 fail with Java 9 related error, but perhaps caused by Java 16
![java - Error: Main.class found in top-level directory (unnamed package not allowed in module) - Stack Overflow java - Error: Main.class found in top-level directory (unnamed package not allowed in module) - Stack Overflow](https://i.stack.imgur.com/qtTO5.png)
java - Error: Main.class found in top-level directory (unnamed package not allowed in module) - Stack Overflow
![How to fix the ''module java.base does not "opens java.io" to unnamed module '' error in Android Studio? - Stack Overflow How to fix the ''module java.base does not "opens java.io" to unnamed module '' error in Android Studio? - Stack Overflow](https://i.stack.imgur.com/PMBGZ.png)
How to fix the ''module java.base does not "opens java.io" to unnamed module '' error in Android Studio? - Stack Overflow
![java - Error: Main.class found in top-level directory (unnamed package not allowed in module) - Stack Overflow java - Error: Main.class found in top-level directory (unnamed package not allowed in module) - Stack Overflow](https://i.stack.imgur.com/FtSx2.png)
java - Error: Main.class found in top-level directory (unnamed package not allowed in module) - Stack Overflow
![java - Error: Main.class found in top-level directory (unnamed package not allowed in module) - Stack Overflow java - Error: Main.class found in top-level directory (unnamed package not allowed in module) - Stack Overflow](https://i.stack.imgur.com/nhlw6.png)
java - Error: Main.class found in top-level directory (unnamed package not allowed in module) - Stack Overflow
![Java 9+ modularity: The difficulties and pitfalls of migrating from Java 8 to Java 9+ - IBM Developer Java 9+ modularity: The difficulties and pitfalls of migrating from Java 8 to Java 9+ - IBM Developer](https://developer.ibm.com/developer/default/tutorials/java-modularity-5/images/Article-4-image_01.jpg)
Java 9+ modularity: The difficulties and pitfalls of migrating from Java 8 to Java 9+ - IBM Developer
Eclipse Community Forums: Java Development Tools (JDT) » Error occurred during initialization of boot layer
![Java-TestBoxing.class found in top-level directory (unnamed package not allowed in module)_₍₍٩( ᐛ )۶₎₎♪的博客-CSDN博客 Java-TestBoxing.class found in top-level directory (unnamed package not allowed in module)_₍₍٩( ᐛ )۶₎₎♪的博客-CSDN博客](https://img-blog.csdnimg.cn/482dd29282f349a29f5ae504f51b50fd.png)