I'm messing arround since hours now with making my site able for https.
I found out, that the plugin Dynamic Content Gallery is using this code:
define( 'DFCG_URL', WP_PLUGIN_URL.'/dynamic-content-gallery-plugin' );
so wordpress-https is not able to fix this I suppose.
as I'm not so good in coding I don't know what I have to change here to make it work with https?
I informed the plugin author as well with your suggestion to use plugins_url instead.
Thanks for help