In fact, the only thing stopping us from using Java 11 is the fact that Nashorn classes are renamed in Java 9 and above.

We may use reflection to solve the problem.

@MidnightSugar
Gotcha, I may push the next updates aside and work on Java 11 support first.

There are plugins that use nashorn that are now incompatible with java 8. To name a few:

• PlaceholderAPI custom javascript placeholders
• MythicMobsExtension
• PlotSquared world scripts

These are the ones I personally know of, there probably is many more. Switching to Java 11 fixes these problems. I've confirmed this.

However, I cannot upgrade because of TR. This needs to be added sooner rather than later.

Sponge API is stuck in Java 8 and will be stuck there for a while, I assume.

Support for Sponge will be paused starting from 3.2.0 until it supports Java 11.