CORS issue with Thingworx and REST calls

Hello everyone,

I am facing the famous CORS issue when making post calls from my java script to the Thingworx Server. To be specific, this is the error message: "...has been blocked by CORS policy: Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource."

I tried to add the CORS filter to the tomcat web.xml as described in this thread and I am still facing this problem. I am using the Trial-Version for Thingworx by the way.

Any ideas what could be the reason?

Any help is appreciated very much.

best Regards,
Dominik