Error Code: e20

[beansprout27]

I can't login to my Steam client but there is nothing wrong with my internet connection and I can login my Steam account at Steam website. At the steam client it says "Connection Problem. There was a problem communicating with Steam. Please try again later" with error code e20. Anyone know how to fix this error? I already try every option that I can find on the internet but none is helpful

[BJWyler]

Did something change in your anti-virus or firewall that is now blocking the client?

[beansprout27]

引用自 BJWyler：

Did something change in your anti-virus or firewall that is now blocking the client?

I didn't change any antivirus/firewall settings before this error happen. The Steam client just suddenly can't connect to the Steam server. After that I try to turn off both antivirus and firewall but still nothing change