LTM Access configuration

Hi, i have APM 11.3 with ltm and i want to configure a scenario where i can access a web service configure behind the Virtual Server and after ACL in the Access policy but just for landing url for the example. i configure it all but i get an error http 404 but when i am connecting from the LAN i can see the web service page. how can i be sure that there is no protocol or other issue like rewrite that making this error? how can i make it "clean connection" but still be able to enforce something?