chgrp "/path/to/dir/." failed: Operation not permitted (1)

[Freshclicks]

The operation is successful in that all of the files transfer over successfully to the proper directory, but this error is causing the rest of the app to fail with
rsync error: some files/attrs were not transferred (see previous errors) (code 23) at main.c(1039) [sender=3.0.6]

[Freshclicks]

So I changed line 305 to
'rsync -rtO %s %s %s %s'
and it resolved the rsync error