https://bz.apache.org/bugzilla/show_bug.cgi?id=64469
--- Comment #5 from Stefan Bodewig <bode...@apache.org> --- you may want to give the graal.js branch a try. https://github.com/graalvm/graaljs/blob/master/docs/user/ScriptEngine.md guided me to unrestrict graal.js so the script is allowed to do as much as the old Nashorn engine would allow. I had to adapt the js example which contained echo.setMessage(i*i); Here Nashorn must have magically translated the Javascript number to a String, graal.js is not willing to go that far (but seems to do so in Nashorn compatibility mode). -- You are receiving this mail because: You are the assignee for the bug.