Major The url of the css of the widgets are wrong. It contains // before :
exemple :
background-image: url('//http://localhost/cms/plugins/gadgets/proxy?container=ametys&gadget=http%3A%2F%2Flocalhost%3A8085%2Fcms%2Fplugins%2Fgadgets%2Fresources%2Fcss%2Fgadget-rss.css&debug=0&nocache=1&url=http%3A%2F%2Flocalhost%3A8085%2Fcms%2Fplugins%2Fgadgets%2Fresources%2Fimg%2Fbullet.png')
<link type="text/css" rel="stylesheet" href="//http://localhost:8085/plugins/gadgets/proxy?container=ametys&gadget=cocoon%3A%2F%2F_plugins%2Fgadgets%2Frss%2Fgspec%3Furl%3Dhttp%253A%252F%252Fwww.telerama.fr%252Frss%252Fmusique.xml&debug=1&nocache=1&html_tag_context=link&url=http%3A%2F%2Flocalhost%3A8085%2Fplugins%2Fgadgets%2Fresources%2Fcss%2Fgadget-rss.css">
