Hi, I am shown as signed in the File Pull down menu but the ArcOnline below it is grayed out. This is also true in the Add Data button extended choices. I am running ArcGis 10.1 on a Windows 7 platform. I suspec t our network firewall may be blocking the attempt. I do not have the test connection in the lower right taskbar tray.
Thanks for the help, I suspect I will have to visit our resident IT team and let them sort it out.
For me, the issue of sign in to ArcGIS Online only happened in Qa and Prod Servers.
The dev server was fine.
Turns out ArcGIS Administrator>Advanced>Manage Portal Connections was only pointing to http://www.arcgis.com/
So, I added AND connected https://www.arcgis.com/ and it worked.
Add the ArcGIS Online organizational domain in ArcGIS Administrator
Maybe the server internet options/proxy whitelist only allowed https arcgis urls in the higher environments (qa/prod) to be more secure.
I also added the appropriate Esri urls to the trusted sites.
These other resources also helped: