Fix: ‘Outlook Data File Cannot Be Accessed’ issue

Many people want to know more about how to Fix ‘Outlook Data File Cannot Be Accessed’ issue. When an Exchange or IMAP email account is set up in MS Outlook, a local file called an Offline Storage File (OST) is created. In the same way, when you add a POP account to Outlook, a Personal Storage Table (PST) file is made. The email server stores a copy of all the information in your mailbox in these Outlook data files (OST and PST). In a nutshell, an OST or PST file is a copy of the user’s mailbox because it stores all mailbox items locally, like emails, attachments, contacts, notes, calendar items, etc.

Even if the system is offline or the Exchange server is down for maintenance or technical problems, users can still use Outlook. In this case, users can keep using Outlook without being stopped. Also, any changes they make to the account or emails they send from Outlook are saved locally in the OST file and synchronized with the mailbox on the server when the system connects to the Exchange server or the server comes online.

When users try to access their mailbox data through the Outlook data file, they could run into problems. There could be a problem with the OST or PST file or Outlook and the email server might not be in sync. Most of the time, problems with the OST or PST file are to blame for access and send/receive errors in the mailbox. We mentioned below are the ways to Fix ‘Outlook Data File Cannot Be Accessed’ issue. If you want to know more information about this Visit Official Microsoft Outlook Support site.

Perform a Clean Boot of the System

Outlook might show the message “data file cannot be accessed” if another program or service on the system is blocking Outlook from getting to its data file. In this case, a clean boot of the system might stop the application or service that is causing the problem from starting, which could fix the problem.

1. Start by giving your PC a clean boot.
2. During the clean boot process, make sure to turn off OneDrive and any services it uses.
3. This is because OneDrive is known to mess up Outlook data files.
4. Once you’re done, open Outlook and see if the Outlook data file accessed problem is fixed.

Repair the Office Installation

1. Restart your PC.
2. Ensure no MS Office processes are running in Task Manager.
3. Right-click on Windows.
4. Choose Apps & Features.
5. Expand Microsoft Office installation.
6. Click the Modify button.
7. In the menu that appears, click on Quick Repair.
8. Click on Repair.
9. Wait for the repair process to complete.
10. Check if the Outlook problem is fixed.
11. If not, repeat steps 1 and 2.
12. Open the Office Repair menu again.
13. Choose Online Repair.
14. Ensure the system is connected to the Internet.
15. Note that this may use a lot of data (around 3GB).
16. Wait for the online repair process to complete.
17. Check if the Outlook data file problem is fixed.

Disable Exchange Cached Mode of Outlook

If the related Outlook account is used in Exchange cached mode, then the “Outlook data file cannot be accessed” error could be caused by corrupted cached data. In this case, you can fix the “Outlook data file cannot be accessed” error by turning off the Exchange Cached Mode in Outlook.

1. Close Outlook, and then use the system’s Task Manager to end all of its related processes.
2. Now, click on Windows, look for the Control Panel, and open it.
3. Then, choose Large Icons from the View drop-down menu and open either Mail or Mail (32-bit). Click on Email Accounts after that.
4. Now, on the Email tab, choose the email account that’s giving you trouble and click Change.
5. Then, open More Settings near the right bottom of the window shown and go to the Advanced tab.
6. Now uncheck “Download Shared Folders” and click “Apply” to save the changes.
7. Then open Outlook and make sure it works well.
8. If not, go to the Email account’s More Settings > Advanced tab (repeat steps 1–5) and uncheck Use Cached Exchange Mode.
9. Then, save the changes and open Outlook to see if the problem with the data file not being accessible has been fixed.

Perform an Inbox Repair by Using the ScanPST Utility

Outlook’s problem with accessing the data file could be caused by a broken data file. If the data file is in the PST format, running an Inbox Repair with the ScanPST utility may fix the problem.

1. Make sure that the system allows you to see hidden and protected operating system files.
2. Close Outlook and make sure that all of its processes in the Task Manager are closed.
3. Right-click on Windows and choose “Run.”
4. Go to the following path according to the Office installation:
   • For Office 64-bit, go to Program Files\Microsoft Office\root\Office16.
   • For Office 32-bit, go to Program Files (x86)\Microsoft Office\root\Office16.
5. Find ScanPST.exe and right-click on it.
6. Click “Run as Administrator,” and in the Inbox Repair Tool, click “Browse” to find the PST file’s location.
7. Click “Start,” and wait for the process to finish. Depending on how big the PST file is, this could take a while.
8. If you get the “PST file is in use” error, do a “clean boot,” and then try the steps above again.
9. Turn off Outlook Sync on a mobile phone, like an iPhone, or turn off the phone altogether, and then try to use the ScanPST utility again.
10. Once you’re done, open Outlook and check if the problem with the data file has been fixed.

Launch Outlook as Administrator

If Outlook doesn’t have permission to access the directory where the Outlook data file is stored as an administrator, it might not be able to access the file. In this case, the problem might be fixed by running Outlook as an administrator. But it’s important to know that when Outlook is started in administrator mode, some features, like the search function, might not work right. Once the Outlook data file has been added successfully, the user can go back to normal mode to use the Outlook client.

1. Close Outlook, and in the system’s Task Manager, close all of its related processes.
2. Now, click on Windows, look for Outlook, right-click on it, and choose “Run as Administrator“.
3. Then, check to see if the problem where the data file can’t be opened has been fixed or if the user can choose the needed Outlook file.
4. If that didn’t work, click Windows, look for Command Prompt, right-click on it, and choose Run as Administrator.
5. Now, do the following (if the Outlook data file is in PST format; if not, change the extension in the command to match the file):
   • icacls *.pst /setintegritylevel m
6. If that didn’t work, try turning off UAC (at your own risk) on the computer in question to see if that fixes the problem.

Why does Outlook data file cannot be accessed message appear?

Here are a few reasons why Outlook 2016 gives you the error “Outlook data file cannot be accessed”:

1. Corrupt user profile: Most of the time, the error was caused by a corrupt profile, and rebuilding the Outlook profile fixed everything.
2. Problems with Microsoft Office: When there are problems with Microsoft Office, they can sometimes cause problems with Outlook and the other programs in the suite.
3. The location of the data file has been changed. If you moved the Outlook files or used a tool to move the data while upgrading, the data file is probably not in the default location and can’t be accessed.