If the certificate issue is fixed then that new issue might be when NeoLoad is sending back the URL to the server. It might not be exactly the same parameters that are sent.

I'm thinking about the blank space that is URL encoded by a "+" in NeoLoad whereas it is a "%20" by the browser. Some applications server does not manage the "+" as encoding caracter.

You could try that procedure to see if it helps:

1. Stop NeoLoad
2. Edit <install_dir>\conf\controller.properties
3. To to [Runtime] section and add in the new line that option: "URL.encode.space.plus=false"
4. Save
5. Start NeoLoad
6. Try a new recording