Summary

This guide helps you troubleshoot and resolve: How to Fix Microsoft Outlook Attachments Not Opening or Downloading in the Desktop App. Follow the steps below to fix the issue.

Common Causes

How to Fix Microsoft Outlook Attachments Not Opening or Downloading in the Desktop App

If you cannot open or download attachments in Microsoft Outlook on your desktop, the issue is often caused by security settings, a corrupted cache, or a problem with your Outlook profile. This guide walks you through the most effective fixes to restore attachment functionality.

Quick Fix Steps

1. Restart Microsoft Outlook and attempt to open the attachment again.
2. Check your internet connection to ensure you can download files from the server.
3. Try opening the email in Outlook on the Web (outlook.office.com) to see if the attachment opens there.
4. Ensure your version of Microsoft 365 is up to date.

Detailed Instructions

1. Clear the Outlook Temporary Files Cache

Outlook stores temporary copies of attachments in a hidden folder. If this folder becomes full or corrupted, new attachments may fail to open.

1. Close Microsoft Outlook completely.
2. Press Windows Key + R to open the Run dialog box.
3. Type %localappdata%\Microsoft\Outlook and press Enter.
4. Delete the contents of this folder.
5. Restart Outlook and try opening the attachment again.

2. Check Attachment Security Settings

Outlook may block certain file types (such as .exe, .bat, or .vbs) for security reasons.

1. Open Outlook and go to File > Options.
2. Select Trust Center from the left-hand menu.
3. Click the Trust Center Settings... button.
4. Select Attachment Handling.
5. Review the list of blocked extensions. If the file type you are trying to open is listed, you may need to ask the sender to use a different file format or share the file via OneDrive or SharePoint.

Warning: Be cautious when unblocking attachment types. Only open files from trusted senders to avoid malware or viruses.

3. Start Outlook in Safe Mode

Third-party add-ins can interfere with Outlook's ability to process attachments. Safe mode disables these add-ins to help you identify the cause.

1. Close Outlook completely.
2. Press Windows Key + R.
3. Type outlook.exe /safe and press Enter.
4. If attachments open successfully in Safe Mode, go to File > Options > Add-ins.
5. At the bottom, ensure COM Add-ins is selected in the Manage dropdown and click Go...
6. Uncheck add-ins one by one, restarting Outlook normally after each change to identify the problematic add-in.

4. Repair Your Microsoft Office Installation

If the issue persists, your Office installation files may be corrupted.

1. Close all Microsoft Office applications.
2. Open the Control Panel on your PC.
3. Go to Programs > Programs and Features.
4. Find Microsoft 365 or Microsoft Office in the list.
5. Right-click it and select Change.
6. Choose Quick Repair first. If that does not work, repeat the process and select Online Repair.
7. Restart your computer once the repair is complete.

Troubleshooting Specific Scenarios

Attachments won't download from a specific sender

If only one sender's attachments are failing, the issue is likely on their end. Ask them to:

• Check the file size (large attachments may be blocked by your mail server).
• Try sending the file as a ZIP archive.
• Upload the file to a cloud service and send a sharing link instead.

Outlook is working in Offline Mode

If Outlook is offline, it cannot download attachments from the server.

1. Look at the bottom of the Outlook window for the status indicator.
2. If it says Working Offline, go to the Send / Receive tab.
3. Click the Work Offline button to reconnect to the server.
4. Wait for emails to sync, then try opening the attachment again.

Note: If you are using an Exchange or Microsoft 365 account, ensure your mailbox is not at its storage limit, as this can prevent new attachments from being downloaded.

If you have tried all the steps above and attachments still will not open, please Open a Ticket with our Brisbane support team for further assistance.

Related Articles

• Setting Up an Email Account in Outlook (POP/IMAP/Exchange)
• Managing Email Signatures in Outlook
• Troubleshooting Outlook Send/Receive Errors
• Backing Up and Restoring Outlook Data Files (.pst/.ost)
• Organizing Emails with Rules and Alerts in Outlook
• Using Outlook Calendar and Scheduling Meetings

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