This usually points to Office 2024 not being fully activated, an account/license mismatch, older license data still cached on the Mac, or some files opening in read-only/locked mode.
Try these steps in order:
- Check activation first
- Open an Office app and confirm it is activated.
- If Excel shows save or edit options as unavailable, sign out from Excel, restart the Mac, then open Excel again and sign in with the Microsoft account that owns Office Home 2024.
- Make sure the correct installer was used
- If Office or Excel was installed from the Mac App Store, remove that version.
- Reinstall Office from the Install option on the Microsoft account Services & subscriptions page.
- Mac App Store Office apps require a Microsoft 365 subscription and may not accept a one-time Office 2024 license.
- Clear old license data if the problem started after switching products
- If there was a previous Microsoft 365 or older Office installation, run the Office License Removal Tool for Mac, restart the Mac, then open Excel and sign in again.
- This clears saved activation data so Office 2024 can reactivate cleanly.
- Open older files directly and resave them in current formats
- Open files from Finder instead of the Recent list.
- If older files are in formats such as .xls or .doc, open them and save them as .xlsx or .docx.
- For co-authoring in Excel, supported formats are .xlsx, .xlsm, or .xlsb.
- If files open but cannot be edited, check for file lock or read-only conditions
- If the workbook is locked for editing during co-authoring, save it in .xlsx, .xlsm, or .xlsb format.
- If the file has password encryption or restricted access, remove that from Review > Protect Workbook on Mac if possible.
- If an add-in is causing the lock, go to Tools > Excel Add-ins and clear the add-in check box.
- Check cloud sync if affected files are in OneDrive or iCloud
- Make sure the files are fully downloaded locally.
- If using the OneDrive sync app, make sure it is up to date and not paused.
- Update Office
- In any Office app, go to Help > Check for Updates and install the latest updates.
- If specific apps fail to open on Apple silicon Macs
- In Finder, right-click Excel > Get Info.
- Make sure Open using Rosetta is unchecked.
If the main symptom is that documents open but cannot be changed, activation is the first thing to fix. If the main symptom is that only older files are affected, open them from Finder and resave them in current formats.