Why am i getting this error with copy/paste?

I am getting an error

Runtime error 1004: Application defined or Object defined error

in my vba code. Could you please help me correct it?

Sub INPUT_DATA()
    ' INPUT_DATA Macro
    ' Application.ScreenUpdating = False
    Application.EnableEvents = False
    Sheets("Input").Select
    If Range("D55").Value = 0 Then
        Range("B2:AI52").Select
        Selection.Copy
        Sheets("Database").Select
        ActiveSheet.Range("A2").End(xlDown).Offset(1, 0).Select
        Selection.PasteSpecial Paste:=xlPasteValues, Operation:=xlNone, SkipBlanks _
            :=False, Transpose:=False
    End If
    Sheets("Input").Select
    MsgBox ("File has been updated. DO NOT PRESS UPDATE again, as it will enter the same data once again")
End Sub