macOS Applescript Error

Hi all, I'm a complete novice to this and I have no background in programming, I work in prepress. I'm trying to set up an hotfolder where our customer services can drop a pdf to have it create a lo/res version for them to email to the customer. On doing some web searching I came across this script

property gsSettinglst : "/gs -dSAFER -dCompatibilityLevel=1.4 -q -dNOPAUSE -dBATCH -sDEVICE=pdfwrite -sOutputFile=?¿?outfile -dPDFSETTINGS=/?¿?quality -dPatternImagemask=true -c .setpdfwrite -f ?¿?infile"
property standardGSPaths : "/usr/local/bin" -- standard paths for gs

property qualities : {"prepress", "printer", "screen", "ebook", "default"}
property folder_names : {"prepress", "printer", "screen", "ebook", "default"}
property magic_bytes : {"%PDF-", "%!PS-Adobe", "≈–”∆"}

property out_folder : "PDFs"


property use_quality : 1



on adding folder items to theFolder after receiving theFiles
main_action(theFolder, theFiles)
end adding folder items to



on run
-- mainly for debugging
set f to choose file
tell application "System Events"
set theFolder to (path of (container of f))
end tell
set theFolder to alias theFolder
main_action(theFolder, {f})
end run

on main_action(theFolder, theFiles)
--try
tell application "System Events"
if not (exists folder out_folder of theFolder) then
make new folder at end of theFolder with properties {nameut_folder}
end if
set f_name to name of theFolder
end tell
set out_path to (POSIX path of theFolder) & out_folder & "/"
--set pathVar to addtoPATH(standardGSPaths)
--set PATHcall to "PATH=" & quoted form of pathVar & ";"

set use_quality to find_in_list(f_name, folder_names)

--display dialog (theFiles as text)
repeat with X from 1 to count theFiles
set curr to item X of theFiles
set file_name to clean_name(curr)

if check_magic(curr) then
set thePath to POSIX path of curr
(POSIX path of theFolder)
set thePath2 to out_path & file_name & ".pdf"
tell application "System Events"
try
(POSIX file thePath2) as alias
set thePath2 to out_path & file_name & " " & my date_string() & ".pdf"
end try
end tell
set thePath to quoted form of thePath
set thePath2 to quoted form of thePath2

--set currCommand to standardGSPaths & gsSettinglst
set currCommand to gsSettinglst
set currCommand to textReplace(currCommand, "?¿?infile", thePath)
set currCommand to textReplace(currCommand, "?¿?outfile", thePath2)
set currCommand to textReplace(currCommand, "?¿?quality", item use_quality of qualities)
set currCommand to standardGSPaths & currCommand

try
do shell script currCommand
log currCommand
tell application "Finder"
delete curr
end tell
on error theError number theNum
if theNum ≠ -128 then
display dialog theError
end if
end try
end if
end repeat
end main_action


--======================================

on find_in_list(the_val, the_list)
repeat with X from 1 to count the_list
if item X of the_list = the_val then
return X
end if
end repeat
return 5
end find_in_list

--======================================

on clean_name(file_ref)
tell application "System Events"
set f_name to name of file_ref
set f_suffix to (name extension of file_ref)
end tell
if f_suffix is not "" then
set suffix_length to (length of f_suffix) + 2
set f_name to characters 1 thru (suffix_length * -1) of f_name as text
end if
return f_name
end clean_name

--======================================


on textReplace(mainText, fromText, toText)
set oldDelims to AppleScript's text item delimiters
set AppleScript's text item delimiters to {fromText}
set textList to every text item of mainText
set AppleScript's text item delimiters to {toText}
set mainText to textList as text
set AppleScript's text item delimiters to oldDelims
return mainText
end textReplace

--======================================

on check_magic(file_ref)
set check_strg to "xxxxxxxxxx"
try
set fh to open for access file_ref
set check_strg to (read fh from 1 to 12)
end try
try
close fh
end try
repeat with X from 1 to count magic_bytes
if (offset of (item X of magic_bytes) in check_strg) = 1 then
return true
end if
end repeat
return false
end check_magic

--======================================

on date_string()
set now to current date
return (((year of now) as string) & "-" & pad_2((month of now) as integer) ¬
& "-" & pad_2(day of now) & " - " & pad_2(hours of now) & "-" & pad_2(minutes of now) & "-" & pad_2(seconds of now))
end date_string

--======================================

on pad_2(num)
set num to num + 100
return ((characters 2 thru 3 of (num as text)) as text)
end pad_2

I then used Hazel to move the pdf into the screen folder from the original folder
and set the script to run on pdf entering the screen folder, on testing this I get the following error
2012-11-07 08:34:59.274 hazelworker[694] Processing folder PDF TEST
2012-11-07 08:35:01.312 hazelworker[694] Done processing folder PDF TEST
2012-11-07 08:35:16.942 hazelworker[698] Processing folder PDF TEST
2012-11-07 08:35:18.960 hazelworker[698] 66455_PL_test.PDF: Rule New Rule matched.
2012-11-07 08:35:19.130 hazelworker[698] [File Event] File moved: 66455_PL_test.PDF moved from folder /Volumes/JobsCurrent/PDF TEST to folder /Volumes/JobsCurrent/PDF TEST/prepress.
2012-11-07 08:35:19.738 hazelworker[698] [File Event] File copied: 66455_PL_test.PDF copied from folder /Volumes/JobsCurrent/PDF TEST/prepress to folder /Volumes/JobsCurrent/PDF TEST/screen.
2012-11-07 08:35:19.782 hazelworker[698] [Error] AppleScript failed: Error executing AppleScript /Library/Scripts/Folder Action Scripts/PDF Convert-1.scpt on file /Volumes/JobsCurrent/PDF TEST/screen/66455_PL_test.PDF.
2012-11-07 08:35:19.782 hazelworker[698] AppleScript error: {
OSAScriptErrorNumberKey = "-1708";

I ran the script through applescript editor and it worked with no errors.
Any help would be greatly appreciated but it may have to be in lay terms sorry

Thanks
ekulmail71