I have followed CS229450 and changed web.xml file and restarted the tomcat service. (cleared tomcat cache)
But still CORS error exists
Access to fetch at 'http://xxxxxxx/Thingworx/Things/xxx/Services/xxx' from origin 'null' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: The 'Access-Control-Allow-Origin' header contains multiple values '*, *', but only one is allowed. Have the server send the header with a valid value, or, if an opaque response serves your needs, set the request's mode to 'no-cors' to fetch the resource with CORS disabled.