Symptom

While the user is attempting a test FSR of an account to Azure, a (403) Forbidden error is experienced?because the user does not have the relevant permissions. This is resolved with some manual permissions changes. However, on the next attempt of a test restore, the following error is presented on the StorageServer multiple times:
 

Unable to write data to the transport connection: An existing connection was forcibly closed by the remote host.

 

Cause

This happens because the public IP of the device where the restore agent is running is not included in Azure's whitelist.

 

Solution

Add the IP address of the relevant device to the approved list in the Azure network resource. To do this:
  1. Open the storage account in Azure.
  2. Go to Firewalls and virtual networks.
  3. Tick the box Add your client IP address.