Workbooks.OpenText Error

opentext doesn't return anything so you need to use

Application.Workbooks.OpenText Filename:=strFileB, Origin:=437, StartRow:=1, _
            DataType:=1, TextQualifier:=xlNone, ConsecutiveDelimiter:=True, _
            Tab:=True, Semicolon:=False, Comma:=False, Space:=True, Other:=False, _
            FieldInfo:=Array(Array(1, 1), Array(2, 1), Array(3, 1), Array(4, 1)), TrailingMinusNumbers:=True
Set tsiB = Activeworkbook