since recent upgrade, multiple ( but not all) sites result in 'proxy server refusing connection'
as above
as above
Tất cả các câu trả lời (2)
see this answer:
Do you need to use a proxy?
You can check the connection settings.
- Options/Preferences -> General -> Network: Connection -> Settings
If you do not need to use a proxy to connect to internet then try to select "No Proxy" if "Use the system proxy settings" or one of the others do not work properly.
See "Firefox connection settings":