Excel Performance Problems

Fix Slow Excel VBA Macros After a Microsoft 365 Update

Maira Mehtab Sep 27, 2026 871 views

Question details

Users report that existing Excel VBA macros run significantly slower than usual following a late August update to Microsoft 365.

Product: Microsoft Excel
Device & OS: not provided
Scenario: Running existing VBA macros in an Excel workbook after updating the Microsoft 365 client.
Observed behavior: The VBA macros experience a severe degradation in execution speed, taking much longer to complete tasks compared to previous software versions.

Before you start

Check your current Microsoft 365 build version by opening Excel, clicking on File, and selecting Account to verify if you are on an affected update release.

Solution 1Recommended

Update Microsoft 365 to a Patched Version

Microsoft has released newer builds that contain a performance fix for this specific VBA macro bug. Updating is the easiest and most effective solution.

Community reports and Microsoft support suggest that updating to build version 17928.20156 or any later supported build resolves the macro execution lag entirely.

Open Account Settings

Launch Microsoft Excel. Click on 'File' in the top left corner, then select 'Account' from the bottom of the left-hand menu.

Check for Updates

Under the 'Product Information' section, click on the 'Update Options' drop-down button.

Apply the Update

Select 'Update Now' from the menu. Wait for Microsoft 365 to download and apply the latest performance patches, then restart Excel and test your macros.

Restart Required: Always remember to completely close and restart all Office applications after an update to ensure the new build changes take effect.

Solution 2

Temporarily Roll Back the Office Update

If you are unable to download the latest patched build or if it has not yet been rolled out to your channel, you can revert Office to a previous stable version.

Solution 3

Submit a Service Request via Microsoft 365 Admin Center

If the issue persists despite updating or rolling back, report the problem directly to Microsoft with your specific workbook and performance data.

Free Microsoft Office alternative

Switch to WPS Office for Reliable Macro Performance

Since this performance issue is tied to a specific Microsoft 365 update, using a stable and lightweight alternative can keep your workflow moving. WPS Office provides excellent compatibility with Microsoft Office formats, and its advanced versions support VBA macros without the disruptive updates.

1. Download and Install: Download WPS Office from the official website and follow the easy installation prompts.
2. Open Your Excel File: Launch WPS Spreadsheet and open your existing .xlsm workbook directly.
3. Run Your Macros: Enable macros if prompted by the security warning, and execute your VBA scripts smoothly.

High compatibility with .xlsx and .xlsm file formats.Stable macro execution environment avoiding recent Microsoft 365 update bugs.Free, lightweight, and fast alternative to heavy Office installations.Familiar user interface for seamless migration and zero learning curve.

microsoft office alternative - wps office

Frequently Asked Questions

How do I check which version of Microsoft 365 I have?

Open Microsoft Excel, click 'File' in the top-left corner, and select 'Account'. Look under the 'Product Information' section for 'About Excel'. Your current version and build number will be displayed there.

Will rolling back my Office update delete my macros or Excel files?

No, rolling back the Microsoft 365 update only reverts the application software to a previous state. It does not delete, modify, or affect your saved personal files, workbooks, or the VBA code within them.

Why do Microsoft 365 updates sometimes make macros slow?

Updates can occasionally introduce bugs or unintended changes to the underlying calculation engine, memory management, or rendering processes that VBA interacts with, which degrades macro performance until a hotfix is released.

Can I prevent Microsoft 365 from updating automatically?

Yes. You can disable automatic updates by opening Excel, navigating to File > Account, clicking the 'Update Options' button, and selecting 'Disable Updates'. However, it is recommended to turn them back on eventually for security patches.

Excel & Data Problems