What does err 522 mean

I am asking for the sum of a column and it is not giving me a total. Instead is says err 522.
I have no idea what that means. Can you help?
Thanks
Sharon

https://help.libreoffice.org/latest/en-US/text/scalc/05/02140000.html

Most possibly, you are trying to put a sum function that refers to the whole column, into a cell in the same column.

There’s a SUBTOTAL function suitable for that.