Microsoft Office / Microsoft 365 errors and troubleshooting

Troubleshoot Microsoft Office and Microsoft 365 startup, document and activation problems. Separate a single damaged file from an application or account issue.

Before choosing a guide

Identify the product, edition and update channel.
Compare the affected file with a new document.
Work on a copy when trying document repair.

Check your product and version →

Related guides 5

◫Microsoft Word for WindowsTroubleshooting guide

Word: Start in Office Safe Mode

Crashes on normal startup

Word for Microsoft 365 / 2024 / 2021 / 2019 / 2016winword /safe

Checked 2026.09.05Read guide ↗

◫Microsoft Excel for WindowsTroubleshooting guide

Excel: Start in Office Safe Mode

Stop at startup

Excel for Microsoft 365 / 2024 / 2021 / 2019 / 2016excel /safe

Checked 2026.09.05Read guide ↗

◫Microsoft Excel for WindowsTroubleshooting guide

Excel: Recover a Damaged Workbook with Open and Repair

Can't open due to corruption error

Excel for Microsoft 365 / 2024 / 2021 / 2019 / 2016Open and Repair

Checked 2026.09.05Read guide ↗

◫Microsoft 365 / Office for WindowsTroubleshooting guide

Office: Fix an “Unlicensed Product” Activation Error

License warning appears

Microsoft 365 Apps / Office 2024 / 2021 / 2019 / 2016Unlicensed Product

Checked 2026.09.05Read guide ↗

◫Microsoft ExcelTroubleshooting guide

Excel file locked for editing: check the owner, location and app

Excel says the file is locked by you or another user

Excel for Microsoft 365 / Excel 2024 / 2021 / Excel for the web; opening a shared workbook

Checked 2026.09.12Read guide ↗