Summary:

Yammer account got disconnected or nothing is displayed.

Symptoms: 

Yammer information of your account is not displayed or available.

Workaround / Resolution:

Try to add https://www.yammer.com to Trusted Sites in Internet Explorer.
Go to Tools -> Options (Security tab).

Status:

This issue has been fixed in Sage CRM 7.2f.


More information:

This  works as expected in Google Chrome