1.16 required arguments for Java 17

The following arguments, in combination with ModernFix, should allow running most 1.16 mods on Java 17.

EDIT: Forge 36.2.41 and later can also run on Java 21. Results will vary depending on how many Java 8 hacks your mods relied upon, but I did test ModernFix and it works.

-Djava.security.manager=allow -Dfile.encoding=UTF-8 --add-opens java.base/jdk.internal.loader=ALL-UNNAMED --add-opens java.base/java.net=ALL-UNNAMED --add-opens java.base/java.nio=ALL-UNNAMED --add-opens java.base/java.io=ALL-UNNAMED --add-opens java.base/java.lang=ALL-UNNAMED --add-opens java.base/java.lang.reflect=ALL-UNNAMED --add-opens java.base/java.text=ALL-UNNAMED --add-opens java.base/java.util=ALL-UNNAMED --add-opens java.base/jdk.internal.reflect=ALL-UNNAMED --add-opens java.base/sun.nio.ch=ALL-UNNAMED --add-opens jdk.naming.dns/com.sun.jndi.dns=ALL-UNNAMED,java.naming --add-opens java.desktop/sun.awt.image=ALL-UNNAMED --add-modules jdk.dynalink --add-opens jdk.dynalink/jdk.dynalink.beans=ALL-UNNAMED --add-modules java.sql.rowset --add-opens java.sql.rowset/javax.sql.rowset.serial=ALL-UNNAMED --add-exports java.base/sun.security.util=ALL-UNNAMED --add-opens java.base/java.util.jar=ALL-UNNAMED

In addition to using these arguments, make sure to disable any Java compatibility check your launcher has built-in, if any.