Nevermind. Problem solved!

"If you're not part of the solution, you're part of the problem" - John McClane,Die hard

What was the answer?

Hi,

My mistake was that I was trying to do both extrusions at the same time instead of one at a time.. Also I forgot the "region" part..

Here's an easy example of my function so that everone can learn from my mistake:

Dim D1, t1, l1 As Double
Dim circle1, circle2 As AcadCircle
Dim reg1, reg2 As Variant
Dim ent(0) As AcadEntity
Dim cylinder1, cylinder2 As Acad3DSolid


pt1 = ThisDrawing.Utility.GetPoint(, "Pick insert point:")

D1 = Val(TextBox1.Text)
t1 = Val(TextBox2.Text)
l1 = Val(TextBox3.Text)

Set circle1 = ThisDrawing.ModelSpace.AddCircle(pt1, D1 / 2)
Set circle2 = ThisDrawing.ModelSpace.AddCircle(pt1, D1 / 2 - t1)

'First extrusion

Set ent(0) = circle1
reg1 = ThisDrawing.ModelSpace.AddRegion(ent)
Set cylinder1 = ThisDrawing.ModelSpace.AddExtrudedSolid(reg1(0), l1, 0)

'Second extrusion

Set ent(0) = circle2
reg2 = ThisDrawing.ModelSpace.AddRegion(ent)
Set cylinder2 = ThisDrawing.ModelSpace.AddExtrudedSolid(reg2(0), l1, 0)

reg1(0).Delete
reg2(0).Delete
circle1.Delete
circle2.Delete

"If you're not part of the solution, you're part of the problem" - John McClane,Die hard