What it means

A 407 Proxy Authentication Required response is similar to 401, but the authentication needs to happen with a proxy server rather than the destination server. The client must authenticate with the proxy before the request can proceed.

Common causes

• A corporate or network proxy requires authentication.
• Proxy credentials were not provided or are invalid.

How to fix it

• Provide valid credentials to the proxy server.
• Check proxy settings in your browser or system configuration.