Starting January 26, 2018, Microsoft will convert Yammer notes into Word Online documents. This function is currently on the top navigation bar in Yammer groups and allows users to create notes in Yammer.
The conversion will occur between January 27-29, 2018. During this time users will have read-only access to their notes. Microsoft will only migrate the last published version; all previous versions and unpublished notes will be lost. Before January 27, 2018, please save any unpublished Yammer notes and make sure to save any previous versions you wish to keep.
After January 30, 2018, Yammer notes will no longer be available, and all your published Yammer notes will be accessible as Word Online documents in your Yammer files.
To learn more about this change, including steps on saving unpublished notes and Frequently Asked Questions (FAQ), please refer to Microsoft’s article: Converting Yammer Notes into Word Online Documents