Recently, an .xlsm workbook of modest size caused Excel to crash upon saving, for both 2013 and 2016 versions. Additionally, Excel would crash with the workbook open while it was just sitting there inactive. Removing conditional formatting from the workbook cured the crash upon save. The workbook has been used for years. We could speculate that a recent Office 2016 update as of last Thursday was connected. In my dept. we often have Excel 2016 crashes; I thought it was important to make this idea public.