I've been having this problem for a long time now. I have a sheet with over 100 formulas. Several months ago, most of the formulas disappeared. I have reentered them from a backup copy and now many of them have disappeared again but not all of them.

I'm pulling my hair out here, many of these formulas are very large and complex. I'm not sure how formulas can go away with just the calculated value remaining in the cell. And again, it's not all of the formulas, just some of them - maybe 30% or so

If my workbook is corrupted somehow, is there a way to repair it?

Thanks a million