Starting with version 3.6.0 Management Console reports the error if a proxy server cannot be authenticated on the MC
Proxy is not authenticated to communicate with the Management Console
Upon installation, when the MC is establishing connection to the proxy server, the Resilio Proxy undergoes regular authentication on the MC.
In some cases the proxy is not authorised/ This may happen, for example, if proxy setup was corrupted in a way, or if it has invalid MC connection credentials in its configuration file, or if the proxy is attempted to be connected to the new MC without having its settings wiped out.
In either case, if MC does not recognise the proxy, it will report the error. There's also a button to reset the connection. Clicking 'Reset now' will clear the storage of the Resilio Proxy effectively wiping out all the current settings. The Resilio Proxy will act as a freshly installed proxy and MC will be able to successfully connect to it.
Error code CE_PROXY_MISSING_CREDENTIALS