If you've stumbled across this article, you're probably getting the following message in the proxy checker:
Error: connection to the proxy server was closed unexpectedly. Please make sure that the proxy server protocol and address are correct.
The reason for that is because HTTPS protocol is selected for the proxy server.
In the test settings, you will need to set HTTP as the proxy protocol. This does not mean that your connection will not be secure. If you connect to the HTTPS website, the SSL protocol will encrypt your information.
Note that if you have not yet enabled HTTP protocol in Proxifier, you will need to do that in the Advanced Settings before the protocol option appears in the Test Settings.
Updated 3 months ago