SharePoint 2013/2016/2019 - RSS Viewer WebPart Error

When working with RSS web part in SharePoint, you get the following error:

"The requested RSS feed could not be displayed. Please verify the settings and url for this feed. If this problem persists, please contact your administrator."

The issue can be resolved by using the following commands:

1. #This command will set the disable intranet - calls value to false.  
2. Add - PSSnapin Microsoft.sharepoint.powershell  
3. $farm = Get - SPFarm  
4. $farm.Properties.DisableIntranetCalls = $false  
5. $farm.Properties.DisableIntranetCallsFromApps = $false  
6. $farm.Update() 

There is a code change in SharePoint 2013 & 2016, SharePoint uses a .NET call to get more information about the address and it failed because our network configuration doesn't allow the DNS resolution of an internet address as well as we are not using the host file entries.

1. System.Net.Dns.GetHostAddresses(System.String)  

Thus, if DisableIntranetCalls is set to true (default), then use .NET call given above to confirm the DNS. However, if DisableIntranetCalls is set to false, then SharePoint will not make this call and use other code to reach the site.