Servoy developer until version 8.2 is build on Eclipse 4.5.0 (mars) or lower, that version of eclipse doesn't work with Java9.

 

Servoy 8.3 will upgrade to Eclipse 4.7 (Oxygen) that eclipse does support Java9 but it could be that the servoy.ini file does need to contain this vm-arg:

--add-modules=ALL-SYSTEM

 

see for more info also the page of eclipse itself: https://wiki.eclipse.org/Configure_Eclipse_for_Java_9

 

See http://openjdk.java.net/jeps/261 for more information about those new Java 9 Module system properties

 

For the smart client we have a page here Java 9 and 10 for smart client