When running a Web Agent, and when a user tries to reach the page:
https://test.example.com/siteminderagent/forms/login.fcc
or
http://myserver2.example2.com:20000/cred/mycustom.fcc?TYPE=[...omitted for brevity...]
with OPTIONS as browser action, the browser receives the return HTTP code 500.
Web Agent all Versions
Web Agent traces show the method OPTIONS isn't supported.
WebAgent.log
Web Agent only accepts GET or POST actions on .fcc file.
The Web Agent only receives the request. The method OPTIONS is sent by the browser, and usually, it's the application that instructs the browser to send the request with the OPTIONS method.
Ensure the request is sent as a GET or POST to the Web Agent .fcc file to solve this issue.