Office Settings & Configuration

Fix PowerPoint Spell-Check Missing Errors on Duplicated Slides

Amos Gikunda Sep 28, 2026 869 views

Question details

The user needs to resolve an issue where PowerPoint's spell-checker works on new slides but fails to detect spelling errors on duplicated slides.

Fix PowerPoint Spell-Check Missing Errors on Duplicated Slides

Product: Microsoft PowerPoint
Device & OS: macOS
Scenario: Proofreading a presentation that contains newly created slides and slides duplicated from a template.
Observed behavior: Spelling errors on duplicated slides are ignored or missed by the spell-check tool, while errors on newly created slides are detected correctly.

Before you start

Ensure you have saved your presentation and check if your version of PowerPoint is updated to the latest release before beginning the troubleshooting steps.

Solution 1Recommended

Test in a New Presentation to Isolate Template Issues

Determine if the spell-check bug is tied to a specific corrupted template rather than the PowerPoint application itself.

Often, formatting anomalies or corrupted text boxes within a specific custom template can prevent PowerPoint's proofing tools from functioning correctly on duplicated slides.

Create a new presentation

Open PowerPoint and go to File > New to create a completely blank presentation without using your custom template.

Insert test text

Type a few words with intentional spelling errors on the first slide.

Duplicate the slide

Right-click the slide thumbnail in the left pane and select Duplicate Slide, then add more spelling errors to the duplicated version.

Run spell-check

Navigate to the Review tab and click Spelling to see if it detects errors on both slides. If it works, your original template is likely corrupted and needs to be rebuilt.

Test in a New Presentation to Isolate Template Issues

Submitting a Sample: If the issue persists even in a blank presentation, you may need to provide your PowerPoint version number and a sample file to Microsoft Support for further investigation.

Solution 2

Clear PowerPoint Cache and Update the Application

Outdated software or corrupted cache files can cause features like spell-check to malfunction on macOS.

Solution 3

Run macOS in Safe Mode

Safe Mode clears system caches and disables background software that might interfere with PowerPoint's proofing tools.

Free Microsoft Office alternative

Try WPS Presentation for Reliable Proofreading

If PowerPoint's spell-check continues to fail on duplicated slides, consider switching to WPS Office. It provides a lightweight, highly compatible alternative with robust built-in spell-checking features that work flawlessly across all slides.

1. Download WPS Office: Download and install the free WPS Office suite from the official website.
2. Open your presentation: Launch WPS Presentation and open your existing .pptx file.
3. Run Spell Check: Navigate to the Review tab and click Spell Check to accurately proofread all slides, including duplicates.

Highly compatible with Microsoft PowerPoint (.ppt, .pptx) formats to ensure your layouts stay intact.Accurate and reliable spell-check across all slides, including duplicates and custom templates.Free, lightweight, and fast-loading on both Windows and macOS.Familiar user interface for seamless and zero-learning-curve migration.

microsoft office alternative - wps office

Frequently Asked Questions

Why does PowerPoint only spell-check newly created slides?

This is often caused by a glitch in the presentation's custom template or a corrupted application cache, which prevents the spell-check engine from recognizing text frames on duplicated slides as new content that needs to be proofed.

How do I check my presentation proofing language settings?

Go to the Review tab, click Language, and ensure the correct proofing language is selected. Additionally, verify that the 'Do not check spelling or grammar' box is unchecked for the text boxes on your duplicated slides.

Can corrupted cache files cause spell-check to fail on Mac?

Yes, corrupted application cache files in macOS can lead to unpredictable behaviors in Office applications, including the failure of the proofing tools. Clearing the PowerPoint cache folder from the macOS Library often resolves these anomalies.

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