If there are any space b/w in the folder name or PDF it will not take.
Rename the PDF as below.
DPro_Consulting_Office_Directions.PDF
so it can open it.
Or in page load u can write as below.
string path = Server.MapPath(@"E:\\uploads\\4876baaf-c10a-494c-8e3c-6efd89fe9c85ADPro Consulting Office Directions.pdf");
IfameId.Attribute.Add("scr",path);