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How to Fix “Unable to Open Outlook Attachment” Error

Published By Ashwani Tiwari
Tej Pratap Shukla
Approved By Tej Pratap Shukla
Published On February 28th, 2022
Reading Time 4 Minutes Reading

Sometimes a user is not able to access email attachments and encounters an “Unable to Open Outlook Attachment” error regarding can’t open the file. This error is caused due to many different reasons and can be solved by some manual and automated methods.

MS Outlook is a leading email client application used by the majority of vertical. This renowned application is used by organizations and business individuals as it manages different activities on a single platform.

But it too has some defects, called as “Outlook errors”, which affects business activities and transactions. One of the defects faced by the user is “cannot open Outlook attachment” error.

The Blog will cover all possible the solutions for this error additionally the reason or cause behind its occurrence.

To Begin with, let’s understand- What is the meaning of this error.

This error refers to the disability of accessing files and folders attached to an email. Being an important part of an email, inaccessibility causes hindrance in work flow.

There are a number of reasons responsible for the cause of this error as listed below. Let’s take a

look at them and find out the causes.

Cause of “Unable to Open Outlook Attachment” Error

Some most of the common and frequent reasons for unwanted error message are:

  • When the user attempts to open or view attachment of an email, whose Outlook data file is already corrupted.
  • The error message is shown when a user with limited access tries to open Temporary Internet file folder on the server.
  • In the case of exceeding the file size of sub-folder storing the copies of Temporary Internet files, the error is often shown.
  • There are times when the error “cannot open Outlook attachment” is also shown when a user opens the same file continuously. The temporary folder will stock up with its temporary file and at some point, the files with the same name are denied to be stored in temporary internet folder. This causes user the inaccessibility of attachments.
  • An attachment with a possibility of damaging the Outlook database is denied from opening due to security protocols.

Pro Tool Tip –  It is recommended to extract attachments from Outlook and access them in other supported email clients to avoid the error.

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Possible Solution for the Error

Various solutions available for “unable to open Outlook attachment” error are explained in the upcoming sections. Find these methods and resolve the error to access your attachments without any trouble.

Method 1: When the Error is Caused by Temporary Internet Folder.

Refer to the following procedure for the solution.

Step 1: From Run command, open REGEDIT.EXE.

Step 2: Click on “Edit Button” followed by “Find” option and type “OutlookSecureTempFolder”.

Step 3: Find the actual folder location and move further with solving the “cannot open Outlook attachment” error like:

C:\Documents and Settings\%USER_NAME\Local Settings\Temporary Internet Files\OLK#\(Where # is a random number or letter)

Step 4: Now, type the file location and click on “OK” at the “Run” command.

Step 5: The Folder will automatically open and delete all the files stored in it.

Step 6: Restart the Browser and open the attachment file in Outlook.

Using this method, the error should be fixed. If not, then try the next method to overcome this issue.

Method 2: When the Error ” Unable to Open Outlook Attachment” is Caused Due to Security Protocols.

In this case, the Security Protocols needs to be edited in the Outlook registry.
The following procedure is used for Windows 10 OS.

Step 1: Open “Run” command and type “REGEDIT.EXE”.

Step 2: Enter Administration password if required.

Step 3: Trace the Registry key that you want to edit.

Step 4: Then, select the “Export” Option From “File” Button.

Step 5: In the export Registry box, type the location where you want to store the backup file and then click on Ok.

Important Note

If you want to solve the error and get rid of this hindrance using an additional and direct help, try the PCVITA Outlook Recovery Tool. This tool will repair any problem related to Outlook data file i.e. either corruption of files or File size issues.

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If you are facing an unable to open Outlook attachment error, then this blog is very helpful for you. Because here in this blog, we have discussed the best possible solution to fix the issue. In addition we have also discussed the best two alternative methods to get rid out of this issue.


By Ashwani Tiwari

I am an Expert Technical Analyst, specialized in assisting users with complex technological challenges. Through my blogs and articles, I offer expert guidance to help tackle these technical issues effectively. My true passion lies in providing valuable insights and simplifying complicated technicalities, enhancing user understanding and confidence.