Glad that worked for you. I’m pretty sure the issue I’m seeing is due to bugs in ACF PRO 5.0.8. I double checked the errors I described above, and would only add that the duplicate nonces are created because acf_admin_field_group::edit_form_after_title() uses the same key as the nonce in acf_input::acf_form_data(). This appears to be by design, because they both use the same nonce validation function, acf_verify_nonce(). This makes me think that the field-group nonce was not properly implemented, and should either be removed or rewritten to use a different nonce (which would affect the nonce verification as well).
Anyway, since this isn’t up on Github yet, here is a patch [http://pastie.org/9611813] for those experiencing these issues. I removed the field-group nonce entirely until the dust settles. I also hook onto ‘pre_post_update’, then remove this action once it’s executed (to avoid a loop).
UPDATE: Read below, don’t apply this patch.
