Getting an error of "error type mismatch" for index match code

JoeUser2004 , i tried your method; there is no error when the code is executed but the index match is only populating the incorrect data; ie those accounts number that are inactive should be populated as inactive in the Lookup for acct status.xlsx file.

I have attached 2 workbooks; Lookup for acct status.xlsx and Corp_Aging.xlsx

Lookup for acct status.xlsx will be workbook that is containing the macro.

Vba code as follows:

Sub idAcc()

Dim ws As Worksheet
Dim agingwb As Workbook
Dim lastRow As Long
Dim i As Long
Dim a As Variant
Dim b As Variant
Dim c As Variant

Set ws = Sheet1
Set agingwb = Workbooks.Open("C:\Users\hrhquek\Desktop\Corp_Aging.xlsx")
ThisWorkbook.Activate

ws.Range("AA1").EntireColumn.Insert
ws.Range("AA1").Value = "Asset_Status"

lastRow = ws.Cells(ws.Rows.Count, "Z").End(xlUp).Row

a = Cells(2, 1)
b = Application.Match(a, agingwb.Sheets("details_open_amt_by_acc").Range("E:E"))
c = Application.Index(agingwb.Sheets("details_open_amt_by_acc").Range("A:A"), b)


For i = 2 To lastRow

Range("AA" & i).Value = Application.WorksheetFunction.IfNa(c, "")

Next i


End Sub