folder action scripts failing: "Finder got an error: Can’t get alias "

drop file in folder with this script attached in folder actions:

on adding folder items to this_folder after receiving added_items

try

tell application "Finder"

set the folder_name to the name of this_folder

set pp to quoted form of POSIX path of this_folder as string

end tell

...

folder exists b/c attached folder action script was triggered