error contents.

An error occurs when migrating to the OpenJDK12 environment.1.The package javax.xml.namespace is accessble from
more than one module: <unnamed>, java.xml

2.The import
com.sun.org.apach.xml.internal.serializer cannot be resolved Please
tell me the solution.

Hi. Thanks for the translation from Japanise on the attached file.

- The package javax.xml.namespace is accessible from more than one module: <unnamed>, java.xml

The system library contains the module "java.xml" with the package 'javax.xml.namespace', but the package 'javax.xml.namespace' is also somewhere contained on the classpath (<unnamed>), in a dependency on the classpath or in your code not having a "module-info.java". You can try to use Java 8 (OpenJDK 1.8) or just update the dependencies (assuming the package 'javax.xml.namespace' is not used in your code). On AOD 8.1.1, please check for the proper Java release you are using under Window->Preferences->Java->Installed JREs. If you search online, there other possible solutions but I don't recommend them: search+remove the dependency/package in your code or exclude the "java.xml" module (maybe they are necessary to the project).

https://stackoverflow.com/questions/61551300/the-package-javax-xml-namespace-is-accessible-from-more-than-one-module-unname
https://stackoverflow.com/questions/51094274/eclipse-cant-find-xml-related-classes-after-switching-build-path-to-jdk-10/53824670#53824670
https://github.com/SpoonLabs/sorald/issues/330


- The import com.sun.org.apache.xml.internal.serializer cannot be resolved

This is very weird, I could not find the exact error message, anyway it sound you are/the end-user is missing a .jar dependency.