Apache Server: Internal Server Error 500 after installing [How to solve]

From xinternetx

I was getting that error immediately after installing, mod_rewrite was ok and chmod was ok.

The solution is in the .htaccess file adding a slash on line 601:

Changing this:

RewriteRule ^(.*)$ index.php?$1 [L,QSA]

for this:

RewriteRule ^(.*)$ /index.php?$1 [L,QSA]