Unable to connect to ArcGIS Servers in ArcCatalog 10.3

[deleted-user-FLZgfcTPnVna]

I am having an issue where I cannot connect to any ArcGIS servers in ArcCatalog 10.3.  I'm able to log into AGS manager via my browser so I know the credentials are good. 

After filling out the dialog box I'm presented with this error.  Any ideas from the hive?

[MichaelVolz]

Is ArcCatalog at the same version as AGS?

Are you using http or https protocol?