To embed a Yammer feed into a SharePoint Team Site you need to use a Script Editor Web Part as I have detailed previously here:
However, as you can see by the above screen shot, when I attempted to do this recently the Script Editor Web Part was not evident. Strange, I thought.
The above image shows the difference and the Script Editor Web Part being available. What was the difference? Why did it appear in one tenant but not in another?
At first, I thought it had something to do with the licensing for the user I was logged in as. However, it turns out that the issue was that scripting hadn’t been enabled for Team Sites in the SharePoint Admin center.
I have previously detailed how missing Web Galleries are also due to scripting not being enabled. My previous post on this as well as how to enable scripting with SharePoint Online is here:
So it turns out that disabled scripting in SharePoint Online also disables some web parts (the Script Editor Web Part being one). Therefore, it is probably good practice to always ensure that scripting is enable in the SharePoint Admin Center before you start building your Team Site.