Hi, This means that the access from your page to the Server is considered by the browser as a CORS request (probably because of the different port).
Consequently, the browser sends a preliminary (i.e. preflight) request to the Server to check if the latter accepts the CORS request.
However, the request is refused because of the presence of the "username" extra http header.

This can be fixed by configuring the Server to allow this header in CORS requests.
This is done in the <cross_domain_policy> block in the Server configuration file, by defining the "accept_extra_headers" attribute accordingly; it should look like:
accept_extra_headers="username"
Then restart the Server and retry (I know you succeeded).

All this matter should be independent from the edition or license with which the Server runs.