Have problems with formatting cells in Excel

If Excel is going into an infinite loop when you try to format cells, it may be related to excessive formatting or a corruption in the workbook. Here are some steps you can take to troubleshoot and resolve the issue:

1. Check for Excessive Formatting: If your workbook has too many different cell formats, it can cause performance issues. In Excel, the limit for different formatting combinations is approximately 4,000 for older versions and 64,000 for newer versions. If you exceed these limits, it may lead to errors or infinite loops.
2. Use the Inquire Add-in: If you have access to the Inquire add-in, you can use it to clean up excess cell formatting. This can help resolve issues related to excessive formatting items. To enable the Inquire add-in, go to File > Options > Add-ins, select COM Add-ins, and check the box next to Inquire.
3. Simplify Formatting: Consider simplifying the formatting in your workbook. Use a standard font across all cells, and avoid applying formatting to entire rows or columns unnecessarily. This can help reduce the number of formatting combinations.
4. Repair the Workbook: If the workbook is corrupted, try opening it in a different version of Excel or using the Open and Repair feature. Go to File > Open, select the workbook, click the arrow next to Open, and then select Open and Repair.
5. Check for Updates: Ensure that you have the latest updates for Excel installed, as updates can fix bugs and improve performance.

If these steps do not resolve the issue, you may need to consider creating a new workbook and copying your data over, ensuring to keep formatting to a minimum.

References:

• You receive a "Too many different cell formats" error message in Excel
• You receive a "Too many different cell formats" error message in Excel

Hi, trygve zetterqvist

Thanks for reaching out to Microsoft Q&A forum.

Sorry for this frustrating experience regarding Format Cells hanging. This usually dues to a bad add‑in, a corrupted style/conditional format, or a compatibility artifact in the workbook.

Here are some workarounds you can try to resolve this issue:

Fix: Excel freezes when opening Format Cells

• Open Excel in Safe Mode to bypass add‑ins: press Windows + R, type excel /safe, then open the affected file and try Home > Number Format > More Number Formats. If it works here, disable third‑party add‑ins before normal relaunch (File > Options > Add‑ins > COM Add‑ins > Go).
• Remove corrupted cell styles: select any affected range, then Home > Cell Styles > Normal to reset; if the Styles gallery is bloated or errors, duplicate only needed styles and delete the rest (Home > Cell Styles > [Control‑click] > Delete).
• Clean problematic custom number formats: open Format Cells > Number > Custom, and delete unusual or very long codes - especially those with many semicolons or color/condition blocks, then reapply simpler codes.
• Trim aggressive conditional formatting: check Home > Conditional Formatting > Manage Rules; remove rules with icon sets, data bars, or cross‑sheet references, which can misbehave in mixed/legacy formats.
• Run Compatibility Checker (if the file is .xls or saved to older formats): File > Info > Check for Issues > Check Compatibility, then resolve listed objects/ActiveX or overflow text issues.
• Update Excel/Windows and input method (IME): freezes linked to IME or older builds were fixed by platform updates, ensure Office and Windows are fully patched.
• Test with a new workbook: copy a few sheets into a fresh .xlsx and retry Format Cells; if the new file is fine, corruption is localized - migrate content gradually and re‑create styles/rules only as needed.
• As a last resort, disable add‑ins permanently or isolate the culprit by re‑enabling one add‑in at a time (COM/Automation add‑ins are frequent offenders).

Tip

When you must keep visual cues without heavy conditional formats, prefer Cell Styles over complex rules, styles are lighter and more predictable across versions.

Thank you for your patience in reading, we hope this information has been helpful to you. 

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