'excel button connected to macro having runtime issue

My vba code connected to a button is crashing on runtime. It is stating sub or function not defined. I am new to vba code so I dont know how to solve this. It appears that the method is closed so I dont know why this is not working. I have added a photo below.

photo

Sub FormButtonClick()
With Shapes(Application.Caller).TopLeftCell.Offset(-1, 0)
    .Value = IIf(Not IsNumeric(.Value), 500, .Value + 500)
End With
End Sub


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