Client authentication methods for ActiveSync isn't configured on this server '{0}'. You can modify this setting via PowerShell. ...

Client authentication methods for ActiveSync isn't configured on this server '{0}'. You can modify this setting via PowerShell.  Example: 'set-ActiveSyncVirtualDirectory -Identity "'{1}'" -BasicAuthEnabled $true' or 'set-ActiveSyncVirtualDirectory -Identity "'{1}'" -ClientCertAuth Accepted' or both to enable authentication support. Click on the link 'get help fixing this issue' in the actions pane located on the right side of the screen for assistance.