When passing a variant array by reference, make sure to use Dim to declare the statement before using Redim.

Example:

 Private Sub Command1_Click()Dim x as integer        ReDim v(2) As Variant    v(0) = "RIN"    v(1) = "A"		    	    Call GetAuthors(v)        Debug.print v(0,0)End SubSub GetAuthors(byref vArray as variant)Dim con As New ADODB.ConnectionDim rs As New ADODB.Recordset    con.ConnectionString = "Driver={SQL Server};Database=Pubs;Server=(local);UID=sa"    con.Open        rs.Source = "select * from AUTHORS where au_lname like '" & vArray(0) & "%'" and " & _ au_fname like '" & vArray(1) & "%'"    Set rs.ActiveConnection = con    rs.Open    vArray = rs.GetRows			'An Error occurs here    rs.Close    con.CloseEnd Sub

Executing this code raises “Run-time error #458 Variable uses an automation type not supported in Visual Basic.” Note that this error is particularly difficult to debug because the compiler will not generate an exception for using Redim without a Dim, event if “Option Explicit” is specified. Declaring the variant with a Dim statement before the Redim will prevent this error from occurring.