Dim counter As Integer
Dim filename As String
Dim problemfile() As String
Dim errorcounter As Integer
Dim i As Integer 'common counter

Sub main()
    '--> Here: Define vault "myvault" etc.
    
    ActiveSheet.Cells(1, 1).Select
    
    While ActiveCell.Value <> ""    'Repeat until empty cell is found
        filename = ActiveCell.Value
        On Error GoTo Error
        '--> Check out file (Lockfile...)
        On Error GoTo 0
        ActiveCell.Offset(1, 0).Select
        counter = counter + 1
    Wend
    MsgBox ("Processed " & counter & "files" & vbCrLf & errorcunter & " errors occured")
    ' Here I will do something with the list of problematic files
    Exit Sub
    
Error:
    errorcounter = errorcounter + 1
    problemfile(errorcounter) = filename
    Resume Next
    
End Sub