I've just a painful time trying to install Secunia's PSI to my new Win 10.
It was bad enough being continually blocked by Microsoft but then Norton kicked in and was warning me about the risks.
The problem is caused by the fact that Secunia is now owned by Flexera and I imagine that Flexera haven't yet completed the required formalities with Norton nor with Microsoft, one of whose screen ranted on about the Certificate not being correct and it could be a site designed to trick me etc etc.
I've told Flexera's Support team but imagine that nothing will happen for weeks.
(And it was made worse by the PSI bumph giving links to screens that are clearly pre-Win10, including the old and familiar Windows Update Centre.)