Answer: How to fix the ''module java.base does not "opens java.io" to unnamed module '' error in Android Studio?

The solution from GitHub has worked for me. It was no need to downgrade Java JDK. Just changed gradle version in gradle-wrapper properties to 7.1.1 (6.x does not support java 16), and adding the following line in gradle.properties:

org.gradle.jvmargs=-Xmx1536M \
--add-exports=java.base/sun.nio.ch=ALL-UNNAMED \
--add-opens=java.base/java.lang=ALL-UNNAMED \
--add-opens=java.base/java.lang.reflect=ALL-UNNAMED \
--add-opens=java.base/java.io=ALL-UNNAMED \
--add-exports=jdk.unsupported/sun.misc=ALL-UNNAMED