When you use Yammer on a mobile browser on an iOS device, such as an iPhone or iPad, you cannot upload and attach files to your posts.
This behavior is by design.
Yammer focuses on delivering a rich native app experience on mobile devices
To work around the issue, install the Yammer iOS mobile app that supports uploading and attaching files to your post.
ID do Artigo: 4035416 - Última Revisão: 18/07/2017 - Revisão: 12