Error 28 Stack Space

I am getting an Error 28 Stack Space error.

Here is my code. The last part of the code "Decide which form to open" is where the error occurs. The file is set up as a survey and it walks them through questions pulling up userforms. This error happens at various times.

Sub NextQ()
'
'

   'Returns to last completed question
    
    Sheets("Emp Sat Sur").Activate
    Sheets("Emp Sat Sur").Range("L" & Cells.Rows.Count).End(xlUp).Activate
    If ActiveCell.Offset(1, -4) <> "" Then
        ActiveCell.Offset(1, -4).Activate
    Else
        Close_usfs.Close_usfs
        usfFinished.Show
    End If


    'closes any open forms
     Close_usfs.Close_usfs

    
    'Decides which form to open
    If ActiveCell.Offset(0, -5).Value = "C" Then usfCTemp.Show
    If ActiveCell.Offset(0, -5).Value = "M" Then usfMisQ.Show
    If ActiveCell.Offset(0, -5).Value = "Q" Then usfQTemp.Show
    If ActiveCell.Offset(0, -5).Value = "S" Then usfSel.Show
    
    
End Sub

My problem was that this file starts by pulling up a userform with various options on it which all lead to another userform with options that lead to another userform etc. etc. etc. Eventually, the Call Stack would fill. I resolved this by using an Unload userform code every time there was a transition from one userform to another. Immediately following the Unload code each time I added the following code:

        Application.OnTime Now, "nextq.nextq"
        End

That set a timer to run the module "nextq.nextq" without an actual time delay. The "nextq.nextq" module loads the next userform. The "End" command "steps out of the code" and resets the stack.