Office for Mac Issues

Fix PowerPoint for Mac "File Is Open by Another User" Error

Bushra Parveen Sep 27, 2026 869 views

Question details

The user is experiencing a false file-lock error in PowerPoint for Mac, where the application claims a presentation is open by another user even when no one else is accessing it.

Fix PowerPoint for Mac "File Is Open by Another User" Error

Product: Microsoft PowerPoint for Mac
Device & OS: macOS
Scenario: Opening or saving a PowerPoint presentation locally or on a shared drive.
Observed behavior: PowerPoint displays an error message stating the file is currently in use or locked by another user, preventing the user from saving or editing the presentation.

Before you start

Verify that the presentation is not actually open on another device or actively being synced by a cloud service like OneDrive. Make a copy of the presentation file to your local Mac desktop before proceeding with troubleshooting.

Solution 1Recommended

Test Saving from a New macOS User Account

Creating a new user profile helps determine if the issue is system-wide or isolated to your current user profile's damaged Office settings.

Often, false file-lock messages are caused by corrupted user profile data or broken permissions within a specific macOS account.

Open System Settings

Click the Apple menu in the top-left corner of your screen and select 'System Settings' (or 'System Preferences' on older macOS versions).

Create a New User

Navigate to 'Users & Groups', click the 'Add Account' button, and follow the prompts to create a new Standard user profile.

Log in and Test

Log out of your current macOS account, log in to the newly created user account, open PowerPoint, and attempt to edit and save the problematic presentation.

Test Saving from a New macOS User Account

Profile Isolation: If saving works perfectly in the new account, the issue is limited to your original profile's Office preferences or local library caches.

Solution 2

Completely Uninstall and Reinstall Office for Mac

If testing in a new user account proves the problem is tied to local settings, a clean reinstallation of Office can resolve deeply corrupted preference files.

Free Microsoft Office alternative

Switch to WPS Office for a Hassle-Free Presentation Experience

If Microsoft Office is failing to reinstall or is constantly locking your files due to profile corruption, WPS Office is a perfect alternative. It is a free, lightweight suite that runs smoothly on macOS without complex profile dependencies.

1. Download the App: Visit the official WPS Office website and download the macOS installer.
2. Install WPS Office: Open the downloaded package and follow the on-screen instructions to install the lightweight app.
3. Open Your Presentation: Launch WPS Presentation and easily open your locked .pptx files to continue editing without false error messages.

Seamlessly open, edit, and save Microsoft PowerPoint (.pptx) files with high format compatibility.Lightweight architecture that avoids the complex macOS user profile and cache corruption issues common in other suites.Completely free to use with a familiar, easy-to-navigate user interface.All-in-one suite includes Presentation, Writer, and Spreadsheet tools in one single application.

microsoft office alternative - wps office

Frequently Asked Questions

Why does PowerPoint say my file is in use when it isn't?

This false file-lock error is usually caused by hidden temporary lock files not being deleted properly when PowerPoint crashed or was closed abruptly. It can also be triggered by cloud sync delays or corrupted macOS user profile settings.

How do I forcibly unlock a PowerPoint file on a Mac?

First, restart your Mac to clear out any temporary lock files. If the file is stored on a shared network or OneDrive, ensure it is completely synced. Alternatively, duplicate the file in Finder, rename the copy, and open the new version.

What should I do if reinstalling Office for Mac fails with an error?

If you encounter installer errors after removing Office, ensure you have completely deleted all Microsoft-related preference files from the Library > Containers directory. Also, make sure your macOS is fully updated and temporarily disable any third-party antivirus software during the installation process.

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