The above image shows 3 cells containing the form
If you are using VBA to enter formulas, it is possible to accidentally enter them incompletely:
Sub AlmostAFormula()
With Range("A1")
.Clear
.NumberFormat = "@"
.Value = "=B1+C1"
.NumberFormat = "General"
End With
End Sub
A1 will appear to have a formula, but it is only text until you double-click the cell and touch Enter .
Make sure you have no bugs like this in your code.