Help! ssl error

browser shows as website not secure,
“This CA Root certificate is not trusted because it is not in the Trusted Root Certification Authorities store.”
ive tried most ssl checkers, they say everything is fine, some return hostname mismatch (cloudflare) which i gather isnt too much of an issue.
can anyone point me in the right direction, as to where the issue actually lies?

A post was merged into an existing topic: Help ssl experts! hostname mismatch issue