Hi Frank,

Based on my test below, I think it is caused by the limitation of formula
property.

Sub test()
Dim s As String
Dim i As Integer
s = "=11111"
For i = 1 To 448
s = s + "+" + CStr(1)
Next
Debug.Print Len(s)
Dim rg As Range
Set rg = Cells(1, 1)
rg.Formula = s
Debug.Print rg.Formula
End Sub

If we change the s = "=11111" to s = "=111111"

the error " 1004 Application-defined or object-defined error" will occur in
the line below.
rg.Formula = s

You may have a try and let me know the result.

Also why you need such a long string formular?
Do you have any concern, maybe we can do that in another way?

Best regards,

Peter Huang
Microsoft Online Partner Support

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