(scrap my previous notion of "not something some obscure win7 patch can solve")
based on petercooperjr's last reply i searched for "trust store
updates windows 7", which yields
and then version i need (x64):
https://www.microsoft.com/en-us/download/details.aspx?id=45633
and this fixes the issue, in both ie11 and brave browser (and all
other chromium based browsers, i would imagine).
prior to this i tried importing certificates (Thejam's reply #32 in
this thread) to no avail (it's easy to install, just dload DER
versions and doubleclick, as article itself doesn't mention way to
install it on 7, it's buried in the comments).
i checked Nummer378's screens to compare with mine (with certification
errors on IE11) and i noticed mention of BOTH X1 and X3 in
"certfication path" tab (the screens he posted) on malfunctioning
system, so i'm inclined to believe that on unpatched system there is a
collision between X1 and X3 ie system doesn't know which path to take
and in the end that means a failure to certify website.
i don't think both can be used at same time....
this system previously had SP1 applied and 6 patches that are needed
to install IE11 (which i needed in order to try onedrive on win7).
Nummner378:
I have even tried a completly clean Win 7 install, installed nothing (just Chrome) - worked out of the box.
probably after windows update finished (and that probably goes for all
your VMs too). i doubt it works with naked 7 and even SP1 alone wasn't
enough in my case....
we didn't mention windows 8(.1): it doesn't have this issue, as tried
inside my VM.
job done.