Yii gives HTTP ERROR 500?

Question

Yii

Hello, do not tell me what the problem is, the site gives an error
"The page is not available The site www.localhost cannot process this request yet.
HTTP ERROR 500"
.htaccess file

Options +FollowSymLinks
<ifModule mod_autoindex.c>
IndexIgnore /
</ifModule>

<ifModule mod_deflate.c>
    AddOutputFilterByType DEFLATE text/plain text/xml application/xml application/xhtml+xml text/css text/javascript application/javascript application/x-javascript
</ifModule>

<IfModule mod_gzip.c>
    mod_gzip_on         Yes
    mod_gzip_dechunk    Yes
    mod_gzip_item_include file  \.(html?|txt|css|js|php|pl)$
    mod_gzip_item_include mime  ^text\.*
    mod_gzip_item_include mime  ^application/x-javascript.*
    mod_gzip_item_exclude mime  ^image\.*
    mod_gzip_item_exclude rspheader ^Content-Encoding:.*gzip.*
</IfModule>

# Cache-Control
<ifModule mod_headers.c>
# 30 дней
<filesMatch "\.(ico|pdf|flv|jpg|jpeg|png|gif|swf)$">
Header set Cache-Control "max-age=2592000, public"
</filesMatch>

# 30 дней
<filesMatch "\.(css|js)$">
Header set Cache-Control "max-age=2592000, public"
</filesMatch>

# 2 дня
<filesMatch "\.(xml|txt)$">
Header set Cache-Control "max-age=172800, public, must-revalidate"
</filesMatch>
</ifModule>

<ifModule mod_expires.c>
    ExpiresActive On
    #по умолчанию кеш в 5 секунд
    ExpiresDefault "access plus 5 seconds"
    #кэшировать флэш и изображения на месяц
    ExpiresByType image/x-icon "access plus 2592000 seconds"
    ExpiresByType image/jpeg "access plus 2592000 seconds"
    ExpiresByType image/png "access plus 2592000 seconds"
    ExpiresByType image/gif "access plus 2592000 seconds"
    ExpiresByType application/x-shockwave-flash "access plus 2592000 seconds"
    #кэшировать css, javascript и текстовые файлы на одну неделю
    ExpiresByType text/css "access plus 604800 seconds"
    ExpiresByType text/javascript "access plus 604800 seconds"
    ExpiresByType application/javascript "access plus 604800 seconds"
    ExpiresByType application/x-javascript "access plus 604800 seconds"
    #кэшировать xml файлы на десять минут
    ExpiresByType application/xhtml+xml "access plus 600 seconds"
</ifModule>

RewriteEngine on

#редирект без www на www
RewriteCond %{HTTP_HOST} ^([^www].*)$
RewriteRule ^(.*)$ http://www.%1/$1 [L,R=301]



#                          /admin,                /backend/web/
RewriteCond %{REQUEST_URI} ^/admin
RewriteRule ^admin\/?(.*) /backend/web/$1

#                         /frontend/web/$1
RewriteCond %{REQUEST_URI} !^/(frontend/web|backend/web|admin)
RewriteRule (.*) /frontend/web/$1

#      frontend
RewriteCond %{REQUEST_URI} ^/frontend/web
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /frontend/web/index.php

#      backend
RewriteCond %{REQUEST_URI} ^/backend/web
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /backend/web/index.php

#RewriteCond %{THE_REQUEST} \s/+(.+?)/+[?\s]
#RewriteRule /$ /%1 [R,L]

.htaccess file /frontend/web/

RewriteEngine On

RewriteBase /
 
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d

RewriteRule . index.php

which is strange, the index.php file which does not open in /frontend/web/, created the file /frontend/web/1.php, everything opens fine ((I can’t understand what is the reason?