I can't save my excel doc. The Save as is greyed out.

Try the following checks and workarounds in order:

1. Confirm the file is not read-only or locked
   • If the workbook is on a shared location (OneDrive, SharePoint, network share, NAS), another user or another Excel instance may have it open in a way that locks editing. In that case, Save/Save As commands can be unavailable.
   • Close Excel completely on all devices, then reopen the file and try again.
   • If opened from a shared location and still locked, use File > Save As / Save a Copy (if available) to save a new copy locally and work in that copy.
2. Check for permission issues on the folder
   • If the workbook is stored on a folder where the account does not have full permissions (read, write, modify, delete), Excel cannot complete the save process and Save/Save As options may be blocked.
   • Move the file to a folder where full access is available (for example, the local Documents folder) and try saving there.
3. Verify disk space and path length
   • Ensure the disk where the file is stored has sufficient free space; if the destination is full, Excel cannot save.
   • If the full path (folders + file name) is very long (over ~218 characters), Excel can fail to save. Move the file to a higher-level folder with a shorter path and try again.
4. Try saving under a new name or different format
   • Use File > Save As (or Save a Copy if the file is in OneDrive/SharePoint) and:
     • Save with a different file name.
     • Save to a different location (for example, Desktop or another local folder).
     • Save as a different Excel type, such as .xlsx or .xlsm instead of .xls.
5. Check for interference from antivirus or other software
   • Some antivirus tools or background processes can interfere with Excel’s temporary file when saving, which can disable or break the save process.
   • If recently installed or updated security software, temporarily disable it and test saving again.
6. Test in Excel Safe Mode (to rule out add-ins)
   • Close Excel.
   • Start Excel in Safe Mode (on Mac, this typically means starting Excel with add-ins disabled via Excel preferences or by removing/renaming startup add-in folders, but the core idea is to run without third‑party add-ins).
   • Open the workbook and see if Save/Save As is still greyed out.
   • If saving works in this minimal state, a third‑party add-in or startup file is likely causing the issue; remove or update that add-in.
7. If the file is on a network or external drive
   • Connection drops or hardware issues can interrupt Excel’s save process and leave commands disabled.
   • Copy the file to the local drive, open it from there, and try saving.

If none of these steps restore Save/Save As, create a new workbook and move the content:

1. In the problem workbook, insert a temporary blank sheet.
2. Group all original sheets (except the temporary one), right-click the sheet tabs, and choose Move or Copy.
3. Move them to a New Book.
4. Save the new workbook to a known-good local folder with a short path and a new name.

References:

• Troubleshoot why Excel doesn't save changes
• File is locked by another user and commands are grayed out
• What is AutoSave?
• SOLVED - Excel 21 stating "Microsoft has blocked macros from running because the source of this file is untrusted." for a network file - Microsoft Q&A
• Excel is no longer registered and can't access some server so it won't let me save anything - Microsoft Q&A