Salesforce Classic Notes & Attachments related list is replaced with Files for attachments and docs and Notes for general notes. If you have not moved your Notes & Attachments records, you will want to do so soon as the related list will eventually be phased out.
Although you can use Notes & Attachments in Lightning it is highly recommended to leverage the New Note button in the Notes related list and Upload Files button in the Files related list instead of continuing to use Notes & Attachments. The easiest way to do this is to remove the Notes & Attachments related lists from the page layout. If you have not moved the records to the new objects, notes can only be read and edited using the method they were created by. To create notes in Lightning Experience, you must use the Notes.
To set up Notes, enable Notes:
- From Setup (gear icon), enter Notes Settings in the Quick Find box and select Notes Settings.
- Make sure Enable Notes is selected.
- Click Save.
If you want to hide feed updates that tell your users whenever someone creates or changes a note:
- From Setup (gear icon), enter Feed Tracking in the Quick Find box and select Feed Tracking.
- If you want to Disable Feed Tracking, uncheck the Enable Feed Tracking box at the top of the page and click Save.
- Select the object you want to turn on/off feed tracking for from the list on the left.
- To hide feeds on Notes, uncheck the All Related Objects box at the bottom of the page.
- Click the Save button.
