Warning: Cannot modify header information

Hi, grat plugin.
I’ve 2 problems, at the moment:

• When I insert a shortcode through editor and save I visualize a blank page with this: Warning: Cannot modify header information – headers already sent by (output started at /home/xxxxxxxx/public_html/confini/wp-includes/class.wp-scripts.php:200) in /home/xxxxxxxx/public_html/confini/wp-admin/post.php on line 197
• On frontend I can’t see images (e.g. http://www.stdigital.it/confini/italia/

Anyone please help me fix them?
Thanks,
Teo

https://ww.wp.xz.cn/plugins/rdp-wiki-press-embed/