Failed To Download Package 'xxxxx' From 'xxxxx/nuget/v3/flat2/xxxxx/xxxxx/xxxxxx.nupkg'. The SSL Connection Could Not Be Established, See Inner Exception

When launching Studio and restoring dependencies, the following error pops up: Failed to download package 'xxxxx' from 'xxxxx/nuget/v3/flat2/xxxxx/xxxxx/xxxxxx.nupkg'. The SSL connection could not be established, see inner exception. Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host"

This issue occurs with the new feed whitelisted on Robots ( With the old feed URL (, all dependencies are resolved correctly and the packages are installed.


Check the network traffic.

If a 303 HTTP status code is being shown, it indicates that the requested resource has been temporarily moved to a different URI or location, and the response should be retrieved using a GET request on the provided location.

In the response, there should be "location" header that contains the new URL where the resource can be found. For example: location: https://{endpointName}

A 303 status code is not an error itself, but instead, it informs the client (Studio, in this case) that it should make a new GET request to the provided location to retrieve the resource. Studio should automatically handle this redirection and download the package from the provided URL specified in the "location" header.


This issue is related to the network setup or security configuration blocking the request to the new URL.

  • Define a white-list entry with the new URL: ( .