Cannot save file as .ods but works as xlsx

For the past couple of days I get an error message “Error saving the document xxxx: Write Error. The file could not be written.” when I attempt to save my ods spreadsheet. If I save the file as a Microsoft Excel spreadsheet (.xlsx) it works perfectly. If I then try to save it as an ods file I again get the error message. It is possible this has something to do with Windows 10 as I recently received an update to version 14393.

I have exactly the same problem on Linux with libreoffice- It is a file that has always been stored as .ods. Now after changing a chart in the spreadsheet, I am not able to save it as .ods any more, only .xlsx.