WebApi returning (401) Unauthorized error

 Hi Guys,

I am facing issue in invoking webApi from SoapUI. The version of the Appian is 16.2. I am getting the below error even after proving the basic authorization and checking pre-emptive authorization in SoapUI.

HTTP/1.1 401 Unauthorized
Date: Wed, 04 Oct 2017 13:51:41 GMT
Server: Apache
Content-Length: 1429
WWW-Authenticate: Basic realm="weblogic"
Keep-Alive: timeout=65, max=501
Connection: Keep-Alive
Content-Type: text/html; charset=ISO-8859-1

Note :

1 . I am successful when trying to invoking it in Appian 17.2 version and followed the same steps.

2 . I gave the authentication details and also checked the pre-emptive authorization.

3. I am working in a bank network and has proxy restrictions.

I am confused whether firewall would cause any issue for invoking webApi. Kindly help me out guys....

Thanks in advance.