500 internal server error what is the reason?

Question

htaccess

Hello... what could be the error?
.htaccess file

ErrorDocument 404 /404.html

# Redirect from www to non-www (never use both)
RewriteCond %{HTTP_HOST} ^www\.(.*)$ [NC]
RewriteRule ^(.*)$ http://%1/$1 [R=301,L]

# Protect .htaccess
<Files .htaccess>
    order allow,deny
    deny from all
</Files>

# Deflate files to fasten the loading
<IfModule mod_deflate.c>
    SetOutputFilter DEFLATE
    AddOutputFilterByType DEFLATE application/x-httpd-php text/html text/xml text/plain text/css text/javascript application/javascript application/x-javascript image/jpeg image/jpg image/png image/gif font/ttf font/eot font/otf
</IfModule>

<IfModule mod_deflate.c>
  # Properly handle old browsers that do not support compression
  BrowserMatch ^Mozilla/4 gzip-only-text/html
  BrowserMatch ^Mozilla/4\.0[678] no-gzip
  BrowserMatch \bMSIE !no-gzip !gzip-only-text/html
  # Explicitly exclude binary files from compression just in case
  SetEnvIfNoCase Request_URI \.(?:gif|jpe?g|png|pdf|swf|ico|zip|ttf|eot|svg)$ no-gzip
</IfModule>

<ifModule mod_headers.c>
  # Enable Keep Alive
    Header set Connection keep-alive
  
  # Properly handle requests coming from behind proxies
  Header append Vary User-Agent
  
  # Turn on Expires
  ExpiresActive On
  
  # Turn off ETag
  <FilesMatch "\.(ico|pdf|flv|jpg|jpeg|png|gif|js|css|swf)(\.gz)?$">
    Header unset ETag
    FileETag None
  </FilesMatch>

  # Set up caching on media files for 5 weeks
  <FilesMatch "\.(gif|jpg|jpeg|png|swf|flv|ico|pdf|avi|mov|ppt|doc|mp3|wmv|wav|ttf|woff|svg)$">
    ExpiresDefault A3024000
    Header append Cache-Control "public"
  </FilesMatch>
   
  # Set up 7 days caching on commonly updated files
  <FilesMatch "\.(xml|txt|html|js|css)$">
    ExpiresDefault A604800
    Header append Cache-Control "proxy-revalidate"
  </FilesMatch>
   
  # Force no caching for dynamic files
  <FilesMatch "\.(php|cgi|pl|htm)$">
    ExpiresActive Off
    Header set Cache-Control "private, no-cache, no-store, proxy-revalidate, no-transform"
    Header set Pragma "no-cache"
  </FilesMatch>
</ifModule>