Fixes / Outlook · Checked September 30, 2026

Outlook data file cannot be accessed (0x8004010F): how to fix it

Short answer

Classic Outlook for Windows can't open the .pst or .ost file your account delivers mail to, so send and receive stops with error 0x8004010F. The usual cause is a corrupted Outlook profile, often because the data file was moved (for example by OneDrive backup). Microsoft's fix is to create a new Outlook profile in Control Panel > Mail > Show Profiles.

What this message means

Outlook stores your mail in a data file: a .pst file for POP and some IMAP accounts, or an .ost file for Microsoft 365, Exchange and Outlook.com accounts. Your Outlook profile keeps the path to that file. When Outlook tries to send or receive and can't open the file at that path, it shows "0x8004010F: Outlook data file cannot be accessed". Usually the mail itself isn't lost. The profile is pointing at a file that has moved, is locked, is damaged, or that your account can't open. Microsoft documents the same error code with a second wording, "The operation failed. An object could not be found."

Common causes

Cause	How to tell
The Outlook profile is corrupted or points to the wrong default data file	You can still read old mail, but every Send/Receive fails with 0x8004010F. Under File > Account Settings > Account Settings > Data Files, the file with the check mark (the default) is not the one you expect, or its path no longer exists.
The .pst file was moved into OneDrive, often by OneDrive's Documents folder backup	The error started soon after you set up OneDrive or PC backup. The Location column on the Data Files tab shows a path containing "OneDrive", and the OneDrive icon may show a sync error or "file in use" for the .pst.
The data file is on a drive that isn't connected (USB drive, external disk or network share)	The Data Files tab lists a drive letter other than C: or a \\server path, and that drive doesn't open in File Explorer, or it opens but the file isn't there.
The .pst or .ost file is damaged	The error persists after a restart, folders may show missing or odd items, and ScanPST reports errors when you scan the file.
The file is locked by another process or has the wrong permissions	Task Manager still shows OUTLOOK.EXE after you close Outlook, or the file's Properties shows it as Read-only. This often happens after copying the file from another PC or user account.

How to fix it

1. Fully close Outlook and reconnect the file's drive

Classic Outlook for Windows (Microsoft 365, 2024, 2021, 2019, 2016)

Close Outlook, then press Ctrl+Shift+Esc to open Task Manager.
If Microsoft Outlook is still listed on the Processes tab, select it and click End task.
If your data file is on a USB drive, external disk or network share, reconnect it and confirm it opens in File Explorer.
Restart the computer and open Outlook again, then press F9 (Send/Receive All Folders) to test.

2. Check where the data file is and move it out of OneDrive

Classic Outlook for Windows, .pst files (POP and some IMAP accounts)

In Outlook, go to File > Account Settings > Account Settings and open the Data Files tab. Note the path of the file with the check mark.
If the path contains "OneDrive", close Outlook and let OneDrive finish syncing.
In File Explorer, copy the .pst to a folder outside OneDrive, for example C:\My Outlook Files, and give the copy a new name.
Open Outlook, go to File > Account Settings > Account Settings, select your account on the Email tab, click Change Folder, then New Outlook Data File, and choose the copied .pst.
On the Data Files tab, select the OneDrive copy and click Remove, then Yes. This only disconnects it and deletes no mail. If Outlook won't let you remove it because it's the default, select the new file and click Set as Default first.
Close Outlook before you delete the old copy from OneDrive.

3. Repair the .pst with the Inbox Repair Tool (ScanPST.exe)

Classic Outlook for Windows. Click-to-Run installs keep the tool in C:\Program Files\Microsoft Office\root\Office16 (64-bit) or C:\Program Files (x86)\Microsoft Office\root\Office16 (32-bit)

Close Outlook.
Open the Office16 folder listed above and double-click SCANPST.EXE.
Click Browse, select the .pst path you noted on the Data Files tab, and click Start.
If errors are found, keep "Make backup of scanned file before repairing" ticked and click Repair.
Run the scan again until it reports no errors, then restart Outlook.

4. Rebuild the .ost file for Microsoft 365, Exchange or Outlook.com accounts

Classic Outlook for Windows, accounts that use an .ost file (the server keeps the master copy)

In Outlook, open File > Account Settings > Account Settings > Data Files and note the .ost path. It is usually %LOCALAPPDATA%\Microsoft\Outlook.
Close Outlook and confirm in Task Manager that it isn't running.
In File Explorer, rename the .ost file (for example add .old to the end) instead of deleting it.
Open Outlook. It creates a new .ost and downloads your mail from the server again. This can take a while on large mailboxes.

5. Create a new Outlook profile (Microsoft's documented fix)

Classic Outlook for Windows 10 and 11. Search for "Control Panel" from Start, since Windows 11 hides it.

Close Outlook. Open Control Panel, switch View by to Small icons, and open Mail (Microsoft Outlook).
Click Show Profiles, select your current profile, click Properties > Data Files, and note the default data file's name and location. Then close that window.
Back in the Mail window, on the General tab, click Add, type a new profile name and click OK.
Enter your email address and password and click Next, then Finish. For a POP account, choose manual setup and pick Existing Outlook Data File to reuse your old .pst.
On the General tab, select Always use this profile, choose the new profile from the list, and click OK.
Open Outlook. If you had other .pst archives, add them back with File > Open & Export > Open Outlook Data File.

6. Clear the Read-only attribute and fix file permissions

Classic Outlook for Windows, .pst files copied from another PC, disc or user account

Close Outlook and browse to the .pst file in File Explorer.
Right-click the file, choose Properties, and on the General tab clear Read-only. Click Apply.
Open the Security tab and check that your user account has Full control. If it doesn't, click Advanced, change Owner to your account, and grant yourself Full control.
Click OK and open Outlook again.

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Still not fixed?

If a new profile with a local, freshly repaired data file still shows 0x8004010F, run Help > Get Diagnostics in Outlook, or download Microsoft Support and Recovery Assistant (SaRA). SaRA can check the profile and Office install, and Office repair is under Settings > Apps > Installed apps > Microsoft 365 > Modify > Online Repair. For a work or school account, contact your IT admin, because the mailbox, permissions or profile may be managed centrally. For a personal POP or IMAP account, ask your email provider to confirm the server settings before you rebuild the profile again.

Questions people ask

Will I lose my emails if I create a new Outlook profile?

No. Creating a profile doesn't delete your old .pst file, and you can point the new profile at it or open it with File > Open & Export > Open Outlook Data File. For Microsoft 365, Exchange and Outlook.com accounts, mail downloads again from the server.

Why can I read old emails but not send or receive?

Outlook can still show what's already in the file, but Send/Receive needs to write new mail to the account's default delivery file. When that file is missing, locked or the wrong one, Send/Receive fails with 0x8004010F.

Can I keep my Outlook .pst file in OneDrive?

Not while Outlook has it open. Microsoft's guidance is to move active .pst files out of OneDrive, because syncing a file Outlook is constantly writing to causes lock and path errors like this one. Store it locally and back it up separately.

Where is ScanPST.exe in Microsoft 365?

In most Microsoft 365, 2024, 2021, 2019 and 2016 installs it's in C:\Program Files\Microsoft Office\root\Office16, or in the Program Files (x86) version of that path for 32-bit Office. Searching the Start menu for SCANPST usually doesn't find it, so open the folder directly.

Does this error happen in new Outlook or Outlook for Mac?

This message comes from classic Outlook for Windows, which relies on .pst and .ost files. New Outlook for Windows and Outlook for Mac store mail differently and don't use this error text.

Sources

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