A SharePoint Online list item attachment doesn't open in the Office client application as expected
Consider the following scenario.
You have a SharePoint Online list item with an attachment present.
You have taken steps to configure SharePoint Online to open documents in the client application by using one or more of the following methods:
- You removed the Office Online license from the affected user account.
- You changed the list's Opening Documents in the Browser setting in Advanced Settings to Open in the client application.
Attachments for list items continue to open in the Internet browser.
To resolve this issue, activate the Open Documents in Client Applications by Default site collection feature in Site settings. To do this, follow these steps:
Click the gear icon to open Settings, and then click Site settings.
Click Site collection features.
If the Site collection features option isn't present, you must first click Go to top level site settings.
Locate the Open Documents in Client Applications by Default feature in the list, and then click Activate.
This setting will affect the behavior of the SharePoint Online site collection.
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