The forum tries to retrieve some resources via HTTP, triggering warnings/errors in the console.
For example, https://forums.ubisoft.com/forumdisp...228-Trackmania gives:

Code:
2228-Trackmania:37 A parser-blocking, cross site (i.e. different eTLD+1) script, https://static5.cdn.ubi.com/u/ubiforums/20130918.419/clientscript/yui/yuiloader-dom-event/yuiloader-dom-event.js?v=425, is invoked via document.write. The network request for this script MAY be blocked by the browser in this or a future page load due to poor network connectivity. If blocked in this page load, it will be confirmed in a subsequent console message. See https://www.chromestatus.com/feature/5718547946799104 for more details.
(anonymous) @ 2228-Trackmania:37
2228-Trackmania:38 A parser-blocking, cross site (i.e. different eTLD+1) script, https://static5.cdn.ubi.com/u/ubiforums/20130918.419/clientscript/yui/connection/connection-min.js?v=425, is invoked via document.write. The network request for this script MAY be blocked by the browser in this or a future page load due to poor network connectivity. If blocked in this page load, it will be confirmed in a subsequent console message. See https://www.chromestatus.com/feature/5718547946799104 for more details.
(anonymous) @ 2228-Trackmania:38
2228-Trackmania:456 Mixed Content: The page at 'https://forums.ubisoft.com/forumdisplay.php/2228-Trackmania' was loaded over HTTPS, but requested an insecure image 'http://static2.cdn.ubi.com/pxm/Trackmania/Forum/Design/Background/Forum_TM_banner.png'. This content should also be served over HTTPS.
2228-Trackmania:535 Mixed Content: The page at 'https://forums.ubisoft.com/forumdisplay.php/2228-Trackmania' was loaded over HTTPS, but requested an insecure image 'http://static2.cdn.ubi.com/pxm/Trackmania/Forum/Design/Background/TM_BLACK_plus_200x63px.png'. This content should also be served over HTTPS.
This does not seem to happen for most of the other categories on https://forums.ubisoft.com/forum.php