When a workbook saves, it is the calculation mode at the time of saving which is saved back into the workbook.
This can become a problem for anybody who does not understand calculation modes.
To your dismay, the ‘Microsoft Excel 2016 is not responding’ error popped up.
After the power resumed, you restarted your system to check the Excel file.
Equally, if Excel is in manual calculation mode, then all workbooks are in manual calculation mode. However, what causes the most confusion is understanding what actions cause the calculation mode to change: From either of these methods it is possible to select automatic, automatic except for data tables and manual as options.
The second method also allows changing the option of recalculating when saving.
The calculation mode is most often set based on the calculation mode of the first workbook opened in the Excel session.
Each Excel workbook contains the setting of the calculation mode at the point it saves.
These two calculation modes can cause issues as they do not always behave as we might expect.