This code is giving me a Run-time error: '9' Subscript out of range:

Dim CDLastRow As Long 'Catalyst Dump
Dim EDLastRow As Long 'Exported Data

CDLastRow = Workbooks("Test Tally SheetII.xlsm").Worksheets _
("Catalyst Dump").Cells(Rows.Count, "A").End(xlUp).Row
Worksheets("Catalyst Dump").Columns("D").ColumnWidth = 13

Per some previous advice I added the file type to "Test Tally SheetII.xlsm"
Since I'm working in 07 and my sheet is saved as .xlsm I used that instead of
..xls. But it locks up on this line still.