[xwiki-users] Missing icons on login page

I'm running a 6.2 wiki that is closed to unregistered users. As a result, people are directed to XWiki.XWikiLogin when they first access the site. On this page I have missing characters (at least when I use Firefox) for they glyph icons (glyphicon-folder-open, glyphicon-home, glyphicon-file, glyphicon-user, glyphicon-lock). These omissions seem to stem from problems with style.css, (although there are quite a few others in the CSS error log), notably: style.css: downloadable font: download failed (font-family: "Glyphicons Halflings" style:normal weight:normal stretch:normal src index:1): status=2147746065 source: https://mysite.net/xwiki/bin/webjars/resources/path?value=bootstrap/3.2.0/f… style.css: downloadable font: download failed (font-family: "Glyphicons Halflings" style:normal weight:normal stretch:normal src index:2): status=2147746065 source: https://mysite.net/xwiki/bin/webjars/resources/path?value=bootstrap/3.2.0/f… I don't have this problem for pages elsewhere in the wiki (default skins everywhere so far). In the main wiki dashboard the glyphs appear fine, and come from the location same URL as before: https://mysite.net/xwiki/bin/webjars/resources/path?value=bootstrap/3.2.0/f… Any idea what the problem is, and how to fix it?