Why am I getting the error "application-defined or object defined error"? - excel

Question

Where is the error application-defined or object defined error coming from? It seems to be coming from the formula that I created. Please help. It really should not be this hard to write code in VBA but for some reason it is not working.
Sub get_levels()
Dim Count As Integer
Dim ticker As Variant
Dim lastRow As Long
Dim lastRowC As Long
Dim rng As Range
Dim current_input_position As Long
Dim sheet As String
Dim mula As String
Dim updatedTicker As String
Application.CutCopyMode = False
Count = 0
sheet = "Test_Sheet"
current_input_position = 2
lastRow = Cells(Rows.Count, "A").End(xlUp).row
Label:
Set rng = Range("A" & current_input_position & ":A" & lastRow)
For Each ticker In rng.Cells
lastRowC = Cells(Rows.Count, "C").End(xlUp).row
updatedTicker = ticker & " A" & " Mtge"
MsgBox updatedTicker
mula = "GCBDC 2018-1A A Mtge"
Range("E2").formula = "=BDS(" & mula & ",""MTGE_CMO_GROUP_LIST"",""Headers=N"")"
Next ticker
End Sub

Answer 1

Assuming your Bloomberg Add-In is functional (try calling BDS manually from a regular worksheet to check), I think you may need to change this line:
Range("E2").formula = "=BDS(" & mula & ",""MTGE_CMO_GROUP_LIST"",""Headers=N"")"
to
Range("E2").Formula = "=BDS(""" & mula & """,""MTGE_CMO_GROUP_LIST"",""Headers=N"")"
If your variable mula has spaces in it (and even if it doesn't), it might need to have " on either side.
(Also, most of your Range and Cells references have no worksheet or workbook specified -- meaning they'll refer to whatever workbook and worksheet happens to be active whilst the code is running. Broadly speaking, you don't want this, but that wasn't your question.)