vanilla 2 broken links

I have a vanilla 2.0.18b2 installation on my webserver in a subfolder. Forum works, but I can't sign in. When I click a link "sign in" the page goes blank. I think that this is a problem with .htaccess file cause I had a working solution but I wanted to change something and broken the file.

Another thing is that, when I am typing forum.mysite.com it says:

Fatal error: Class 'Gdn' not found in /bootstrap.php on line 47

when I type mysite.com/forum it view the website but with no styling, and when I click a link it goes 500 Internal Error.

Only when I type mysite.com/forum/index.php it looks normal.

My .htaccess file looks like that:

# Modified
# If you modify this file then change the above line to: # Modified
<IfModule mod_rewrite.c>
   RewriteEngine On
   # Certain hosts may require the following line.
   # If vanilla is in a subfolder then开发者_如何学C you need to specify it after the /. 
   # (ex. You put Vanilla in /forum so change the next line to: RewriteBase /forum)
   RewriteBase /forum/
   RewriteCond %{REQUEST_FILENAME} !-d
   RewriteCond %{REQUEST_FILENAME} !-f
   RewriteRule ^(.*)$ index.php\?p=$1 [QSA,L]
   #RewriteRule ^$ index.php/$1
</IfModule>

Try clearing the cache by deleting all the files and folders inside the cache folder. Was facing the exact same problem and clearing the cache solved the issue!

Try changing the RewriteRule to this RewriteRule ^(.*)$ index.php?p=$1 [QSA,L]