excel - Application defined or object-defined error when opening a second workbook -

i have code open 1st workbook, open 2nd workbook, copy range 1st workbook , paste in 2nd workbook.

 sub test()         '**variables**         dim folderpath string         folderpath = "y:\plan_graphs\final\mich_alco_test\files\"         dim filetitle string         filetitle = "5.xlsx"          dim dataworkbook workbook         set dataworkbook = application.workbooks.open(folderpath & filetitle)          'dim resultworkbook workbook         'set resultworkbook = application.workbooks.open("y:\plan_graphs\final\mich_alco_test\result.xlsx")          dim copyrange range         set copyrange = dataworkbook.worksheets("list1").range("a3:f3", range("a3").end(xldown))          copyrange.copy         'resultworkbook.worksheets("1").range("a3").pastespecial paste:=xlpasteformulas   end sub 

but application defined or object-defined error error on line

set copyrange = dataworkbook.worksheets("list").range("a3:f3", range("a3").end(xldown))      

when comment lines related second workbook, no error happens. why error happen?

edit: interesting thing is, if define , set copyrange before opening 2nd workbook, works fine... i'm curious of opening 2nd file messes copyrange , why opening file later helps.

it depends workbook have active when run code.
line of code potentially looks @ 2 different workbooks:
set copyrange = dataworkbook.worksheets("list").range("a3:f3", range("a3").end(xldown)).

dataworkbook.worksheets("list").range("a3:f3" - looks @ list sheet in dataworkbook.

range("a3").end(xldown) - looks @ activesheet in resultworkbook when lines aren't commented out.

use:
set copyrange = dataworkbook.worksheets("list").range("a3:f3", dataworkbook.worksheets("list").range("a3").end(xldown))

or

with dataworkbook.worksheets("list")     set copyrange = .range("a3:f3", .range("a3").end(xldown)) end