VBA Function

[Jojo890]

I wrote this VBA function for Excel but it doesn't work. Can someone help me to find out the error?
Thank's a lot!

Option Explicit
Option Base 1
Function HPJ(data As Range, lambda As Double) As Variant
    Dim nobs As Long
    Dim i As Long, k As Long
    Dim HPout() As Variant
    Dim K1() As Variant, K2() As Variant, K3() As Variant, K4() As Variant, K5() As Variant, K6() As Variant
    nobs = data.Rows.Count
    
    ReDim HPout(1 To nobs)
    For k = 1 To nobs Step 1
        HPout(k) = data(k)
    Next k
    
    ReDim K1(nobs - 2, nobs)
    For i = 1 To nobs - 2 Step 1
        For k = 1 To nobs Step 1
            K1(i, k) = 0
            If i = k Then K1(i, k) = 1
            If i = k + 2 Then K1(i, k) = 1
            If i = k + 1 Then K1(i, k) = -2
        Next k
    Next i
    
    ReDim K2(nobs, nobs - 2)
    For i = 1 To nobs - 2 Step 1
        For k = 1 To nobs Step 1
            K2(k, i) = K1(i, k)
        Next k
    Next i
    
    ReDim K3(nobs, nobs)
    For i = 1 To nobs Step 1
        For k = 1 To nobs Step 1
            K3(i, k) = 0
            If i = k Then K3(i, k) = 1
        Next k
    Next i
    
    ReDim K4(1 To nobs)
    ReDim K5(nobs, nobs)
    ReDim K6(nobs, nobs)
    
    K5 = Application.WorksheetFunction.MMult(K2, K1)
    
    For i = i To nobs Step 1
        For k = 1 To nobs Step 1
            K5(i, k) = lambda * K5(i, k)
        Next k
    Next i
    
    For i = i To nobs Step 1
        For k = 1 To nobs Step 1
            K6(i, k) = K5(i, k) + K3(i, k)
        Next k
    Next i
    
    K4 = Application.WorksheetFunction.MMult(Application.WorksheetFunction.MInverse(K6), HPout)
    
    
    HPJ = K4
    End Function