Cakephp internal server error

If you are stand on Root folder

your .htaccess should like

 <IfModule mod_rewrite.c>  
   RewriteEngine on  
   RewriteRule  ^$ app/webroot/  [L]  
   RewriteRule  (.*) app/webroot/$1 [L]  
 </IfModule>  

If you are stand in to app folder

your .htaccess should like

 <IfModule mod_rewrite.c>  
    RewriteEngine on  
    RewriteRule  ^$  webroot/  [L]  
    RewriteRule  (.*) webroot/$1  [L]  
 </IfModule>