After the first workbooks.open, the opened workbook is the active
workbook, so your reference to Sheets("files").Range(..) is invalid
unless the just opened workbook has a worksheet named "files".

Try:

With ThisWorkbook.Sheets("files")
Workbooks.Open .Range("C3").Value
Workbooks.Open .Range("C4").Value
End With

In article ,
Jim Cottrell wrote:

I would like to open 4 files with a macro. If I just open one file it works.
If I try to open more than one, I get a subscript out of range error.
Can you help me with this?
Thanks!

Workbooks.Open Sheets("files").Range("C3").Value
Workbooks.Open Sheets("files").Range("C4").Value