I'm using a firefox proxies plugin and this message show up, what this means?

The proxy server is refusing connections

Firefox is configured to use a proxy server that is refusing connections.

Check the proxy settings to make sure that they are correct.
Contact your network administrator to make sure the proxy server is
working.

I'm using a firefox proxies plugin and this message show up, what this means?

your proxy seems to be dead, thats when you get such errors.. Make sure the proxy is working and you entered its details properly

are you using a private proxy or public proxies ?