How can I change AEM 6.4 Java VM, runtime

If you use AEM version of JQuery - it has a token that takes care of CORS issues. Create a clientlib and then add dependencies property with value of cq.jquery. 

Adobe Experience Manager Help | Developing for Cross-Origin Resource Sharing (CORS) with AEM

Ok will do. Will mark this correct if I get it successfully done.

Thanks for fast reply!

Still getting the AJAX error. Can't even get to save a Sharing Policy which is the first step to generate a new Policy. I'm assuming it's the jdk version? we're using JDK 8u181. we have installed JDK 8u191 but AEM still uses the old JDK version. how can we let it use the updated version?

THANKS!

OpenJDK is not supported, look here what is exactly supported: Technical Requirements

Thanks for the reply!

Yes seen that. That's why I upgraded only to JDK 8u191.

but if so, do you propose any other fix to the AJAX error I'm getting when saving a CORS Sharing Policy?