Problem with code execution in production.

Hi ;
I have an web application which display images on the main page and this application is located in a DMZ.
The code functions perfectly in a development environment but ignores the image in production.
I verified this with Fiddler.
Our systems people say this is a code issue but the production code worked before the only differnce now is that I am pointing to a different URL.
Here is my code :
  string myPath = "https://www.somewebsite.com/images/path1/path2/path3/" + "name of Image" + .jpg"
   If (checkMyUrl (myPath == true))
    {
         img.imageurl = myPath;
     }
    else
     {
         img.imageurl = default.image;
      }
 & ...