I am assuming you are using the Desktop application included with Adobe Acrobat Professional XI.
I can give you a few things to try:
Try exiting out of the application and then launch and sign back in again, server connection problems can be difficult to diagnose but are often fixed by restarting things. Are you inside of a firewall at a company that might block some ports or types of traffic?
Also, you can try to "repair" the application following these steps:
And - one sure method to at least get your form online is: