Sub Test()
  On Error Resume Next
  Dim O1 As New Class1
  O1.DoSomething
  On Error GoTo 0
End Sub

Sub DoSomething()
  FindStuff

  'create similar objects who perform similar operations and raise similar errors
  Dim O2 As New Class2
  O2.DoSomething
End Sub

Function FindStuff() As Stuff
  'scan the WorkBook, the file system, etc. and organize the members of the object
  If CorruptedFileSystem Then Err.Raise 514, "File system corrupted"
  If CorruptedWorkBook Then Err.Raise 515, "WorkBook corrupted"
  If Found Then Set FindStuff = FoundStuff
End Function

Sub Test1()
  Dim O As New Class1
  O.UnhandledCall
End Sub

Sub Test2()
  On Error Resume Next
  Debug.Print 1 / 0
  Dim O As New Class1
  O.HandledCall
  On Error GoTo 0
End Sub

Sub UnhandledCall()
  Debug.Print 2 / 0
End Sub

Sub HandledCall()
  Debug.Print 3 / 0
End Sub

Sub Test()
    Dim foo As Class1
    Set foo = New Class1
    'On Error Resume Next
    foo.DoSomething
    'On Error GoTo 0
End Sub

Sub DoSomething()
    Err.Raise 5
End Sub

If CorruptedFileSystem Then Err.Raise 514, "File system corrupted"
If CorruptedWorkBook Then Err.Raise 515, "WorkBook corrupted"

If CorruptedFileSystem Then Err.Raise 514, "Class1.DoSomething", "File system corrupted"
If CorruptedWorkBook Then Err.Raise 515, "Class1.DoSomething", "Workbook corrupted"