Are you trying to do this from Excel?

OpenDatabase requires a string as its argument, so DaoConStr should be declared as a string, not a Name object.

'How to Open Another MS Access Database from Your Database
'This will read a field in a table from another database that is not open and then closes it

    'Opens another database from the current open database
Dim app As Access.Application
Dim wks As Workspace
Dim db As Database
Dim rst As DAO.Recordset
    Set app = New Access.Application
    Set wks = app.DBEngine(0)
    Set db = wks.OpenDatabase("C:\DBs Flex-3rd\SubjectsMain-Access-VBA_BE")
    Set rst = db.OpenRecordset("AabTS_Constants", dbOpenSnapshot)

'Do Until rst.EOF
'        Debug.Print rst!RootDoc_ImgFolder
        Me.txtResult = rst!RootDoc_ImgFolder.Value
'Call ListFieldsAndTypes(rst)
'rst.MoveNext 'remember this or it goes forever!
'Loop
rst.Close
Set rst = Nothing
Set db = Nothing
Set wks = Nothing
app.Quit

Wow,  That is so helpful.  I can accs the db whenever I want.