Lightning Experience: Attachments are being replaced by Files and not returned in search
|Knowledge Article Number||000233850|
|Description||When performing a search within Lightning Experience users may report that Attachments are not returned in search results.
|Resolution||This is expected behavior and due to Attachments being deprecated in Lightning Experience. Attachments are being superseded and replaced in favor of the more robust Files feature. For more details on Files see Files Overview.
Lightning Experience users can still view legacy attachments on records however, they will not be returned in search results when performing a search from within Lightning Experience.
For organizations who have both Lightning Experience and Salesforce Classic users, it is highly recommended to enable the org feature, "Files uploaded to the Attachments related list on records are uploaded as Salesforce Files, not as attachments."
See Upload Files to Notes & Attachments List in Salesforce Classic for more details but enabling this feature ensures that any attachments added to records will be uploaded as Files so that Lightning Users are able to search for them within Lightning Experience. Attachments uploaded after enabling this feature will be returned in Lightning search results under Files.
In order to locate Attachments that have been added prior to enabling this feature Lightning Users will need to temporarily switch to Salesforce Classic to perform a search there in order to locate legacy attachments.
Considerations for enabling the enhanced note-taking tool (Notes) and using Files