Adobe Sign documents - Recently, IE incorrectly reports "The Cookie functionality is disabled.."

This started for me about 2 weeks ago.  The document renders fine in Chrome and Firefox, and renders fine if the user is running Windows 10.  But if you are running something less than Windows 10, than any version of IE shows this error. 

We have not updated our application in over a month, and customers across the US are calling us to report the issue.  Adobe is insisting they have not changed anything.

We are currently telling callers to add "echosign.com" to their list of trusted sites, but obviously this is not ideal.

Is anyone else seeing this issue?