The Nashorn scripting implementation has been removed from OpenJDK 15 onwards, as it was difficult to keep it up to date with the latest Javascript developments. The javax.script API is still present and third party implementations, such as Rhino or Nashorn itself, can be installed if needed.

When
a Java class references:

• jdk.scripting.nashorn
• jdk.scripting.nashorn.shell

Perform
add a hint that the code either needs to be removed or a dependency on the now external Nashorn library introduced

References
https://openjdk.org/jeps/372
https://github.com/openjdk/nashorn