I have a problem where when I insert a formula such as ='Sheet21'!F3, the
cell shows the formula, instead of the result. This isn't consistent
apparently. I have managed to copy the formula from another cell that works,
but when I then change the cell ref (e.g F3 to F4 in the above example), the
cell displays the formula again, instead of the result. Cell format is
"Text". Is this a cell formatting issue??