Error en código

Soy totalmente nuevo en la materia....y el código sería el siguiente:

Option Explicit

Sub DimenDESG()

Dim t1, t2 As Worksheet

Dim file As Byte Dim Fd, F, manufacturer, steel, dfi, b1, b2, h, FI, B, H2, fy, fu As Integer

Fd = t1.Cells(10, 2)

file = 9

F = t2.Cells(file, 1)

manufacturer = t1.Cells(16, 2)

steel = t1.Cells(14, 2)

Do While Fd > F

file = file + 1

F = t2.Cells(file, 2)

Loop

Do

F = t2.Cells(file, 2)

If manufacturer = 1 Then

dfi = t2.Cells(file, 2)

b1 = t2.Cells(file, 3)

b2 = t2.Cells(file, 4)

h = t2.Cells(file, 5)

Else

dfi = t2.Cells(file, 6)

b1 = t2.Cells(file, 7)

b2 = t2.Cells(file, 8)

h = t2.Cells(file, 9)

End If

B = b1 + 5

FI = dfi + 5

If B <= 40 Then

If steel = 1 Then

fy = t2.Cells(3, 2)

fu = t2.Cells(3, 3)

ElseIf steel = 2 Then

fy = t2.Cells(4, 2)

fu = t2.Cells(4, 3)

Else

fy = t2.Cells(5, 2)

fu = t2.Cells(5, 3)

End If

Else

If steel = 1 Then

fy = t2.Cells(3, 4)

fu = t2.Cells(3, 5)

ElseIf steel = 2 Then

fy = t2.Cells(4, 4)

fu = t2.Cells(4, 5)

Else

fy = t2.Cells(5, 4)

fu = t2.Cells(5, 5)

End If

End If

H2 = 0.5 * Fd / B / fy * 1.05 + 2 / 3 * FI

file = file + 1

Loop While H2 > h - 20
t1.Cells(20, 2) = F

t1.Cells(21, 2) = b1

t1.Cells(22, 2) = b2

t1.Cells(23, 2) = dfi

t1.Cells(24, 2) = h

t1.Cells(21, 5) = B

t1.Cells = h
End Sub

Gracias por adelantado por su ayuda! Saludos!