Is there a problem with only this one attachment?
Can you provide the specific content or screenshot of this error?
Are there problems with other types of documents? If only word attachments have problems, follow these steps and uncheck the options:
Open a blank Word document, go to File > Options> Trust Center > Trust Center Settings > Protected View, then uncheck Enabled Protected View for Outlook Attachments.
According to the error message, another possible cause is that the Windows Firewall service is not running, or You are using Outlook on a Windows 8-based, Windows 8.1-based, or Windows Server 2012-based computer.
To resolve this issue, start the Windows Firewall service. To do this, follow these steps:
- Press the Windows logo key+R (to open the Run dialog box).
- Type services.msc, and then select OK.
- In the Services window, right-click Windows Firewall, and then select Start.
- Empty the Deleted Items folder and other unimportant folders like Junk Mail, Drafts, etc. Hope this helps!
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