A few features of SharePoint Online in Office 365 have recently been retired (rather abruptly) or are slated to go in the next year.
First up, Tags & Notes. In a support article titled SharePoint Online Tags & Notes feature retired on the Office support site you can learn all about what this means and potential downstream impacts. Microsoft’s advice? Use Yammer.
Here’s what we recommend as an alternative to Tags & Notes:
Next up, we have SharePoint Online and Task synchronisation going the way of the dodo. Over on the MS support site, KB 2998485 - The “Tasks” link and “Sync to Outlook” button are missing from a personal site in SharePoint Online informs us that the Tasks option will be disappearing from SharePoint Online in the very near future. Microsoft’s advice? Stop syncing Tasks to Outlook.
If you’re currently syncing a SharePoint tasks list to Microsoft Outlook, tasks will continue to sync for approximately one year following this announcement. The personal Tasks page will also continue to be available for one year. After that time, this functionality will be removed and will no longer be available or supported.