Maybe you may try these instructions.
set original to "Main-Storage:Comtech-Art:V:Vyve:201569 Vyve channel lineup cards (81):HOLD!!!!!:201569 Vyve Lineup Herington - KS.pdf"
set dest to "Macintosh HD:Users:corei7user:Dropbox: Blue"
# Some instructions checking that the paths point to existing items
tell application "System Events"
exists disk item original
log result
exists disk item dest
log result
end tell
# Instruction duplicating the original file in the dest folder
do shell script "cp " & quoted form of POSIX path of original & space & quoted form of POSIX path of dest
Two instructions check that the paths are pointing to existing items.
The late one use do Shell script to duplicate the file.
I tried one more time to use System Events duplicate command but it continue to fail with error message : Erreur dans System Events : Files can not be copied. number -1717
Yvan KOENIG running El Capitan 10.11.4 in French (VALLAURIS, France) mercredi 13 avril 2016 20:54:19