In case Excel is showing some weird errors like Excel cannot save the workbook at all, it is worthy to check that all the updates are implemented correctly.

This is not a waterproofed solution but rather a hint how you can start with this issue.

In Excel select file – account.

Check updates with update now button.

Office (and Excel) was up to date.

To check Windows 10 updates, press square in lower left hand corner and select settings.

Then choose Update & Security.

Press Check for updates.

All updates are in.

If any updates are installed, restart the computer even though it was not required.

If Excel for some reason cannot save document or something is corrupted, updates do not necessarily solve the issue. It is the first thing every user can do to have latest updates both for Windows and Excel.