Problems with Slider

hi there,

i have a issue when i want to create a slider.
the slider is shown, but also a undefinied index message.
or if i want to delete a section from the demo-content.
could you please have a look?
the enfold version is 3.6 (wordpress runs at 4.5) and i read your post “f you have troubles since the update to WordPress 4.5 please read this post before opening a new thread.”

and after that:
i´ve got also now the problem: Cannot modify header information – headers already sent by (output started at /www/htdocs/w011ae22/limo-2016/wp-includes/functions.php:3897) in /www/htdocs/w011ae22/limo-2016/wp-includes/pluggable.php on line
(i know the “normal” reason, but it isn´t it the case).
i fixed it already, i took the old functions-files again.

thank you!