Sometimes when I select a range of cells to copy to another spreadsheet, the result on the new spreadsheet is blank. And then if I save that new spreadsheet, it won't open later because the datat is 'corrupt'.
My current workaround is to save the original spreadsheet to a CSV file, close then re-open and select the cells again and then copy to new spreadsheet. Apparently saving to a CSV strips not only all the formatting but also the 'corrupt' crap. Losing all the formatting is a pain, but is still quicker than re-typing all the info. this happens even when copying from an xlsx to another xlsx.