MS Outlook is a feature-rich app that users use on a daily basis. However, various errors do arise in it from time to time. One of them is the Outlook operation failed error. It occurs when you attempt to use or launch specific Outlook functions. It can also arise if you are using an older Outlook version. As a result of it, you are unable to attach files to your Outlook emails. You’ll find the ‘Operation failed‘ message on the screen whenever you try to do so. This error will not let you execute even the basic tasks, such as creating notes or accessing Outlook settings. If you are facing this error, this article will help you know about its causes and ways to troubleshoot it.  

Read Also:- Why Outlook Not Showing Attachments

Reasons for the Outlook Operation Failed Error

There is not one but several causes for this error message to display. Here are the major ones.

• Your Outlook application runs in a compatibility mode, so some components cannot work properly.
• Outlook has not been installed fully.
• A corrupt .PST file will also result in the Operation Failed in Outlook.
• If you are using an obsolete Outlook version, you can face this error.
• Conflicting applications also result in this problem.
• There are faulty add-ins in Outlook.
• Some duplicate rules haven’t been set properly.
• There is an issue with draft folder permission.

Read Also:- Why Outlook Working Offline

Fixes for Outlook’s Operation Failed Attachment Error

There are quite many ways to resolve this error. Before using the methods mentioned below, access your system with admin rights.

1. Find Problematic Add-Ins

Various add-ins that enhance Outlook’s functionality can conflict with each other resulting in this error. You will need to find the defective add-in and disable it to solve the problem. 

• Open the Outlook program and tap ‘File.’
• Tap ‘Options‘ followed by ‘Add-ins.’
• You’ll see a window showing all the add-ins on your screen. 
• Go to the end of this window. Here, choose ‘Manage: COM Add-ins.’
• Now, hit ‘Go.‘
• Remove the checkmarks from the add-ins you wish to disable and tap ‘OK.’
• After that, see if this error resolves. 

2. Run Outlook in Non-Compatibility Mode

If you are currently using Outlook in compatibility or normal mode, you’ll face an Outlook email operation failed attachment error. It’s best to try using Outlook in non-compatibility mode to fix the issue. 

• Right-tap on Outlook’s icon and choose ‘Properties.’
• Tap the ‘Compatibility‘ tab. 
• Remove the tick from the ‘Run this program in compatibility mode option.
• Tap ‘Apply’ followed by ‘OK.’
• Now launch Outlook and examine if the error has been fixed.

3. Use the Latest Version of Outlook

Microsoft launches Outlook updates so you can use a high-performing application. To find out if your Outlook version is the latest or not. If it’s not, use these measures to update it.

• Hit ‘File‘ after opening Outlook.
• Now, tap ‘Office Accounts.’
• Next, click ‘Office Updates.’
• Choose the ‘Update Now option.
• Now, you won’t find the ‘Operation Failed‘ message showing on the screen.

4. Make Another Outlook Profile

As mentioned before, if the Outlook profile is corrupt or damaged, you will face the Operation Failed Outlook error. There can be many reasons for the profile becoming corrupted. They include unusually large PST files, Outlook crashing suddenly, or users terminating the application because of issues such as power failure. In these cases, it’s best to make a new profile. Before making one, backup your Outlook data.

• Find the ‘Control Panel‘ area in your system, open it and select ‘Mail.’
• Go below ‘Mail Setup – Outlook.‘
• Here, hit the option ‘Show Profiles.‘
• Now, click ‘Add.’
• You can now name your Outlook profile.
• After that, fill out all the necessary information, such as your password and email address. 
• Now, whenever you open MS Outlook, use this newly formed profile.
• Choose the prompt for a profile and tap ‘OK.‘
• To find the new profile, restart Outlook in safe mode.
• You can now select the new profile from the dropdown list.
• Lastly, exit Outlook and restart it in the usual manner.

5. Clean Boot Your Windows

Another method to fix the error is to clean the startup services. Here is how to clean boot Windows. 

• Launch the ‘Run‘ dialog box. You can do it by hitting the Windows key and R together. 
• Input ‘Msconfig‘ and tap ‘OK‘ to go to ‘System Configuration.’
• Choose the button ‘Selective Startup.’
• Now, select ‘Load System Services‘ and the options of ‘Original Boot Configuration.’
• Remove the tick beside the ‘Load Startup Items‘ box. 
• Launch the ‘Services‘ tab and click the ‘Hide Microsoft Services‘ option.
• Now tap the ‘Disable All‘ button. This action will deselect every third-party service. 
• After that, tap ‘Apply‘ followed by ‘OK.’
• In the dialog box window, tap the ‘Restart‘ option. 

6. Fix the Configuration Issue in Outlook

Suppose you find the Outlook operation failed error on trying to send a message. In that case, it means that your Outlook has an incorrect configuration. This error will arise when you have configured Google apps sync for your Outlook and Exchange server accounts in one profile. 

In order to fix it, make a few profiles. One of them should be linked to the Exchange server, and the other should be set up with Google apps sync. 

7. Modify the Connection Mode of Outlook

Outlook links with the Exchange server through online mode and cached mode. If it encounters an issue linking to the Exchange server, it will result in this error message. So, you can modify the connection mode with the Exchange server.

• Tap’ File‘ in the application.
• Hit the ‘Account Settings‘ dropdown followed by ‘Account Settings.’
• Choose your account in the ‘Email‘ tab.
• Hit ‘Change.’
• Tap ‘More Settings‘ in the box of ‘Exchange Account Settings.’
• Tap ‘Advanced‘ and enable the option ‘Use cached exchange mode.’
• Restart Outlook.

8. Modify HTML Format of Messages to Rich Text

Are you encountering this error when you make a message with HTML, like a logo or an image? You can troubleshoot the problem with the draft’s permission on the HTML side of a message. Modifying its format to rich text will eliminate the issue.

• In Outlook, open the affected message.
• Now, launch the ‘Format Text‘ tab in the window of ‘Message.’
• Go to the ‘Format‘ group and modify the ‘HTML‘ format to ‘Rich Text.’
• Save and close the email.
• Open it and tap ‘Format Text.’
• Now, change the format to ‘HTML.’
• Open the message again and send it to see if there is any problem with Outlook’s functioning.

Final Thoughts

These simple ways will help you tackle the Outlook Operation Failed error. You will now be able to attach files to the emails in this application. However, if these methods don’t prove useful, it’s recommended to take the help of an Email Technical Support service.