I have a workbook with multiple worksheets that I have been using all year
but all the sum functions have now stopped auto-updating. So if I type a new
value into one of the cells that make up the "sum" the sum does not change.
If I try to copy and paste the sum function from the next column, it retains
the value of the original sum. If I manually type a new sum formula into the
cell it returns the correct value.

All values are numbers not text strings.

Any suggestions gratefully received!

It could be that you've altered how Excel calculates.

Go to Tools --- Options --- Calculation

Check to see if it's set to manual.

HTH.

"Paul" wrote:

I have a workbook with multiple worksheets that I have been using all year
but all the sum functions have now stopped auto-updating. So if I type a new
value into one of the cells that make up the "sum" the sum does not change.
If I try to copy and paste the sum function from the next column, it retains
the value of the original sum. If I manually type a new sum formula into the
cell it returns the correct value.

All values are numbers not text strings.

Any suggestions gratefully received!