This message appears because SSL(https) can be applied to the LMS login screen, which cannot be applied to next pages.When using Chrome, this kind of problem has not reported yet.
However, the problem appears in Explorer(IE).
Therefore, when you want to use LMS using Explorer, the following procedures can be used to solve the issue.(1) IE Tools Menu on the upper right > 'Internet Options' > 'Security' Tab(2) Click 'Trusted Sites' > 'Site' Click
(3) Add Trusted Sites