Hi @sina,
I moved your post from the old thread here: Single journal url .htaccess configuration - #31 to a new post here. that was an older thread, so it is best to start a new one.
For the 500 errors, could you please have a look in your PHP error log and report on errors from there?
Could you also indicate the version of OJS you’re using (e.g. 3.3.0-13), in the future, please include this in your posts.
-Roger
PKP Team