Archive link gives Forbiden server error

Ok, I didn't noticed this before, but one user told me that going to archive link gives this error:

Forbidden
You do not have permission to access this document.

I have default settings, so I'm wandering is it normal behavior, or not? And if not, what is wrong with my server settings. It seems it is not normal behavior of redirecting archive to sitemap.

I have archive directory and there is index.php file. And it works normally when I disabled vBSEO and went directly to /archive/index.php.

Also, when I go to /sitemap/ (without anything specified) I get aforementioned error.

If I go to some directory, for example /sitemap/f1 (this is wrong link, I just realized) it works. Even as it is wrong link, archive becomes functional. And it works if I use correct links.

So, question is, why going to /sitemap/ without anything after it gives back error? What should I change?

Now I noticed that after going to some thread in archive map I go to thread in forum, not archive...

Try enabling

Options +Multiviews

at the very top of your htaccess file

It didn't helped.

But, I looked at my server and noticed that I have sitemap directory. It's used by vBulletin's own sitemap. I renamed that directory to sitemap2 and now everything works fine. If there's actual directory we redirect archive to, it doesn't work and reports error. I'm not sure if that's supposed to be so, but assume it.

Also is it supposed that archive threads are showed as actual threads? I see forum home as archive (vBulletin's default archive), I see forums as archive, but when I go to threads, I see them as normal threads. Is that ok? Just asking...

vBSEO Has an option to redirect archive threads to live threads