Paste in your action script, and be sure to use the blockquote (highlight it and select the </> icon in the Wiki editor).
If your line really is
wait //Clean-up Temp files, this should not need to change
delete "_Download/{parameter "app_file_name_PSE"}"
then that’s an error. The “wait” command requires a parameter - the command to execute. You can’t have
wait //comment
any more than you can have
wait
by itself.
Maybe you intend something like
wait "__Download/{parameter "app_file_name_PSE"}"
//Clean-up Temp files, this should not need to change
delete "__Download/{parameter "app_file_name_PSE"}"