Question on the post run script here too.
From the help:
"Runs the selected script AFTER everything is done. Sent arguments: post-run, destination path, true|false (true on backup success, false otherwise)"
Are these positional arguments being sent?
So:
$1="post-run"
$2="/path/to/where/appdata_backups/puts/the/backups/" # Is there a trailing slash or no?
$3="true OR false"