Says "You can't edit a cell in a locked column"

But the column is not locked!

I am trying to double click a calculation column so I can add the columns to add together but it won't let me.

Have turned off default locked column and made sure lock icon is gone.

TIA

Hi TIA,
That message appears because you were copy/pasting and you have not cancelled it yet thus the app thinks you're trying to paste a cell into a calculation.
You have to click on the 'cancel copy' icon (a square with an X in it) on the top bar and you'll be able to edit that column.
We'll improve that unfortunate error message in our next update

Kind regards,
Bert

I was having this same issue. Thank you for the explanation.