{
               addcors.AllowAnyOrigin()
                   .AllowAnyMethod()
                   .AllowAnyHeader();
           }));

My API URL is giving me CORS Error in Mozilla Firefox, but in other browser there is no error. I have tried many methods like changing the '''about:config''' but it didn't make any difference. Its been days I am facing this issue. Kindly help. Thanks in Advance. FRONTEND : Angular. BACKEND : Dotnet core API. Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at <MY WEB API URL>. (Reason: CORS request did not succeed). Status code: (null). '' Dotnet code for API services.AddCors(o => o.AddPolicy("MyPolicy", addcors => { addcors.AllowAnyOrigin() .AllowAnyMethod() .AllowAnyHeader(); })); app.UseCors("MyPolicy");''