Adam's final two questions are directly on point.
Has this ever worked for the form you mentioned? That is crucial to resolving this issue.
The problem with security certs is that sometimes the developers forget that there are web requirements on cert names because that is how you get pages to be trusted. This MIGHT be something simple as having a link that jumps to a folder that is NOT a sub-directory of the home URL. I.e. let's say the site starts in folder C:\SiteHome and that it drills down in sub-folders thereof. BUT let's say that one of the pages jumps you to C:\Junkyard for some reason. If the root folder of the cert is for C:\SiteHome, you just jumped out of the certificate's scope. That isn't your fault.
So the next question is, how do you get to that site that your web control referenced, AND did you derive that link from the web link on some other page? I.e. from where did the web link originate. A followup question is whether your browser gets the same message if you manually try to get there? Because if it does, the problem isn't likely to be on your end.