.htaccess to remove html from url not working - html

Question

I want to rewrite: www.example.com/guides.html to www.example.com/guides
I rewrote the htaccess file using almost every version found here in stackoverflow and could get it to work.
Im currently navigating to the url like this:
GUIDES
If i try in my development server using:
http://localhost:3000/guides
I get
"Cannot GET /guides".
If i try it in my production server I get:
"Internal Server Error
The server encountered an internal error or misconfiguration and was
unable to complete your request.
Please contact the server administrator at webmaster#example.com to
inform them of the time this error occurred, and the actions you
performed just before this error.
More information about this error may be available in the server error
log.>
Additionally, a 500 Internal Server Error error was encountered while
trying to use an ErrorDocument to handle the request."
This is my htaccess file:
<IfModule mod_expires.c>
ExpiresActive On
ExpiresDefault A0
ExpiresByType image/gif A691200
ExpiresByType image/png A691200
ExpiresByType image/jpeg A691200
ExpiresByType text/css A691200
ExpiresByType text/javascript A691200
ExpiresByType application/javascript A691200
</IfModule>
ErrorDocument 401 "Unauthorized"
ErrorDocument 403 "Forbidden"
<IfModule mod_negotiation.c>
#Options -MultiViews
</IfModule>
RewriteEngine On
RewriteBase /
#### PERSISTENT CONTENT ####
#### PERSISTENT CONTENT END ####
DirectoryIndex index.php index.cgi index.html
RewriteCond %{REQUEST_FILENAME} !-f [OR]
RewriteCond %{REQUEST_URI} ^\/(js\/main\.js|css\/(\d+|common|site)\.css)$
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_URI} !^/\.well-known/cpanel-dcv/[0-9a-zA-Z_-]+$
RewriteCond %{REQUEST_URI} !^/\.well-known/pki-validation/(?:\ Ballot169)?
RewriteCond %{REQUEST_URI} !^/\.well-known/pki-validation/[A-F0-9]{32}\.txt(?:\ Comodo\ DCV)?$
RewriteRule ^(.*)$ sitepro/$1 [L,QSA]
#### PERSISTENT CONTENT ####
RewriteCond %{HTTP_HOST} ^www\.example\.com$
RewriteCond %{REQUEST_URI} !^/\.well-known/cpanel-dcv/[0-9a-zA-Z_-]+$
RewriteCond %{REQUEST_URI} !^/\.well-known/pki-validation/(?:\ Ballot169)?
RewriteCond %{REQUEST_URI} !^/\.well-known/pki-validation/[A-F0-9]{32}\.txt(?:\ Comodo\ DCV)?$
RewriteRule ^/?$ "https\:\/\/example\.com\/" [R=301,L]
And here's how i modified it:
<IfModule mod_expires.c>
ExpiresActive On
ExpiresDefault A0
ExpiresByType image/gif A691200
ExpiresByType image/png A691200
ExpiresByType image/jpeg A691200
ExpiresByType text/css A691200
ExpiresByType text/javascript A691200
ExpiresByType application/javascript A691200
</IfModule>
ErrorDocument 401 "Unauthorized"
ErrorDocument 403 "Forbidden"
<IfModule mod_negotiation.c>
#Options -MultiViews
</IfModule>
RewriteEngine On
RewriteBase /
#### PERSISTENT CONTENT ####
#### PERSISTENT CONTENT END ####
DirectoryIndex index.php index.cgi index.html
RewriteCond %{REQUEST_FILENAME} !-f [OR]
RewriteCond %{REQUEST_URI} ^\/(js\/main\.js|css\/(\d+|common|site)\.css)$
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_URI} !^/\.well-known/cpanel-dcv/[0-9a-zA-Z_-]+$
RewriteCond %{REQUEST_URI} !^/\.well-known/pki-validation/(?:\ Ballot169)?
RewriteCond %{REQUEST_URI} !^/\.well-known/pki-validation/[A-F0-9]{32}\.txt(?:\ Comodo\ DCV)?$
RewriteRule ^(.*)$ sitepro/$1 [L,QSA]
#### PERSISTENT CONTENT ####
RewriteCond %{HTTP_HOST} ^www\.example\.com$
RewriteCond %{REQUEST_URI} !^/\.well-known/cpanel-dcv/[0-9a-zA-Z_-]+$
RewriteCond %{REQUEST_URI} !^/\.well-known/pki-validation/(?:\ Ballot169)?
RewriteCond %{REQUEST_URI} !^/\.well-known/pki-validation/[A-F0-9]{32}\.txt(?:\ Comodo\ DCV)?$
RewriteRule ^/?$ "https\:\/\/example\.com\/" [R=301,L]
## hide .php extension
RewriteBase /
RewriteCond %{REQUEST_URI} \.html$
RewriteRule ^(.*)\.html$ $1 [R=301,L]

Answer 1

Turns out by chance I stumbled upon an article that mention that i needed 'Options +MultiViews' before writing the rules. It is working now, at least for my production server.