After upgrading to androidstudio 3.0 gradle stopped working:

Unable to resolve dependency for ':app@debug/compileClasspath': Could not resolve com.android.support:appcompat-v7:26.1.0.

Could not resolve com.android.support:appcompat-v7:26.1.0.
Required by:
 project :app

> 
> Could not resolve com.android.support:appcompat-v7:26.1.0.
>  Could not get resource '<https://dl.google.com/dl/android/maven2/com/android/support/appcompat-v7/26.1.0/appcompat-v7-26.1.0.pom>'.
>  Could not GET '<https://dl.google.com/dl/android/maven2/com/android/support/appcompat-v7/26.1.0/appcompat-v7-26.1.0.pom>'.
>  Connect to dl.google.com:443 [dl.google.com/172.217.22.110] failed: Connection timed out: connect
>  Connection timed out: connect
> 
> 
> 

I have checked the proxy and it works.

This is a new project, nothing was changed from what the android studio wizard generates.

Thanks for your help.